diff --git a/CHANGELOG.md b/CHANGELOG.md
index aebbd4ece..8afe363d1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,10 +10,12 @@ _None_
 
 ### New Features
 
+- Add `generate_release_notes_file` to write generated GitHub Markdown into a version section in existing release lanes. [#776]
 - Add an opt-in `fail_on_error` mode to translation download actions so GlotPress request and response errors fail CI jobs. [#771]
 
 ### Bug Fixes
 
+- Pass the configured release notes path to GitHub using the expected `configuration_file_path` parameter. [#776]
 - Bump `fastlane` to `~> 2.240` to require `rubyzip >= 3.4.0`, fixing CVE-2026-85396 / GHSA-47m2-wp7j-p9vc. [#775]
 
 ### Internal Changes
diff --git a/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/generate_release_notes_file.rb b/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/generate_release_notes_file.rb
new file mode 100644
index 000000000..e83816f5e
--- /dev/null
+++ b/lib/fastlane/plugin/wpmreleasetoolkit/actions/common/generate_release_notes_file.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require 'fastlane/action'
+require_relative 'get_prs_between_tags'
+require_relative '../../helper/release_notes_helper'
+
+module Fastlane
+  module Actions
+    class GenerateReleaseNotesFileAction < Action
+      def self.run(params)
+        UI.user_error!('An explicit previous_tag is required to generate release notes') if params[:previous_tag].to_s.empty?
+        version = params[:version]
+        UI.user_error!('Expected a numeric release version') unless version.match?(/\A\d+(?:\.\d+){0,2}\z/)
+
+        path = params[:release_notes_file_path]
+        contents = File.read(path)
+        options = params.values.except(:version, :release_notes_file_path, :dry_run)
+        markdown = other_action.get_prs_between_tags(**options, fail_on_error: true)
+        section = "#{version}\n-----\n#{markdown.rstrip}\n\n"
+        updated = Helper::ReleaseNotesHelper.update_section(contents: contents, version: version, section: section)
+
+        if params[:dry_run]
+          UI.message(section)
+        else
+          File.write(path, updated)
+        end
+        section
+      end
+
+      def self.description
+        'Write generated GitHub Markdown to a RELEASE-NOTES.txt version section'
+      end
+
+      def self.details
+        <<~DETAILS
+          Inserts or replaces one version section using get_prs_between_tags, preserving other versions and header comments.
+          Keeps the returned Markdown, including headings, authors, contributors, and links.
+          Use configuration_file_path to exclude or group PRs by GitHub labels; no title markers are needed.
+          For a separate report, such as release testing, call get_prs_between_tags with its own configuration_file_path.
+          Requires an explicit previous_tag and a published target_commitish if tag_name does not exist.
+          Use dry_run to preview without writing. Does not commit changes.
+        DETAILS
+      end
+
+      def self.available_options
+        GetPrsBetweenTagsAction.available_options.reject { |option| option.key == :fail_on_error } + [
+          FastlaneCore::ConfigItem.new(key: :version, description: 'Numeric version heading in RELEASE-NOTES.txt', type: String),
+          FastlaneCore::ConfigItem.new(key: :release_notes_file_path, description: 'Existing release notes file', type: String, default_value: 'RELEASE-NOTES.txt'),
+          FastlaneCore::ConfigItem.new(key: :dry_run, description: 'Preview the section without writing the file', type: Boolean, default_value: false),
+        ]
+      end
+
+      def self.return_value
+        'The generated version section'
+      end
+
+      def self.authors
+        ['Automattic']
+      end
+
+      def self.is_supported?(platform)
+        true
+      end
+    end
+  end
+end
diff --git a/lib/fastlane/plugin/wpmreleasetoolkit/helper/github_helper.rb b/lib/fastlane/plugin/wpmreleasetoolkit/helper/github_helper.rb
index 9402794db..f2c6cf193 100644
--- a/lib/fastlane/plugin/wpmreleasetoolkit/helper/github_helper.rb
+++ b/lib/fastlane/plugin/wpmreleasetoolkit/helper/github_helper.rb
@@ -311,7 +311,7 @@ def generate_release_notes(repository:, tag_name:, previous_tag:, target_commiti
           tag_name: tag_name,
           target_commitish: target_commitish, # Only used if no git tag named `tag_name` exists yet
           previous_tag_name: previous_tag,
-          config_file_path: config_file_path
+          configuration_file_path: config_file_path
         )
         res.body
       end
diff --git a/lib/fastlane/plugin/wpmreleasetoolkit/helper/release_notes_helper.rb b/lib/fastlane/plugin/wpmreleasetoolkit/helper/release_notes_helper.rb
index dc6cf12a7..8f9441828 100644
--- a/lib/fastlane/plugin/wpmreleasetoolkit/helper/release_notes_helper.rb
+++ b/lib/fastlane/plugin/wpmreleasetoolkit/helper/release_notes_helper.rb
@@ -3,6 +3,31 @@
 module Fastlane
   module Helper
     module ReleaseNotesHelper
+      VERSION_HEADING = /^\d+(?:\.\d+){0,2}\r?\n[-=]+\r?\n/
+
+      # Insert or replace one version, preserving other sections and line endings.
+      # @param [String] contents Existing RELEASE-NOTES.txt contents.
+      # @param [String] version The section to replace or insert.
+      # @param [String] section The generated version section.
+      # @return [String] Updated file contents.
+      def self.update_section(contents:, version:, section:)
+        sections = contents.split(/(?=#{VERSION_HEADING})/)
+        versions = sections.map { |part| part.lines.first.chomp if part.match?(VERSION_HEADING) }
+        first_version = versions.index { |value| value }
+        UI.user_error!('No version headings found in the release notes file') unless first_version
+        UI.user_error!("Duplicate release notes sections for #{version}") if versions.count(version) > 1
+
+        newline = contents.include?("\r\n") ? "\r\n" : "\n"
+        section = section.gsub(/\r?\n/, newline)
+        index = versions.index(version)
+        if index
+          sections[index] = section
+        else
+          sections.insert(first_version, section)
+        end
+        sections.join
+      end
+
       # Update the release notes file (typycally RELEASE-NOTES.txt) to add a new entry.
       #
       # @param [String] path The path to the release notes text file.
diff --git a/spec/generate_release_notes_file_spec.rb b/spec/generate_release_notes_file_spec.rb
new file mode 100644
index 000000000..e277a0381
--- /dev/null
+++ b/spec/generate_release_notes_file_spec.rb
@@ -0,0 +1,148 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Fastlane::Actions::GenerateReleaseNotesFileAction do
+  let(:header) { "*** Generated at code freeze.\n\n" }
+  let(:history) { "25.6\n-----\n- [Internal] Keep this historical entry\n" }
+  let(:original) { "#{header}25.7\n-----\n- Handwritten draft\n\n#{history}" }
+  let(:markdown) do
+    <<~MARKDOWN
+      <!-- Release notes generated using configuration in .github/developer-release-notes.yml at trunk -->
+
+      ## New PRs since [25.6](https://github.com/woocommerce/woocommerce-android/releases/tag/25.6)
+
+      ### Changes
+      * Fix checkout by @developer in https://github.com/woocommerce/woocommerce-android/pull/123
+      ### Android Wear
+      * Update navigation by @bot[bot] in https://github.com/woocommerce/woocommerce-android/pull/124
+      ## New Contributors
+      * @developer made their first contribution in https://github.com/woocommerce/woocommerce-android/pull/123
+
+      **Full Changelog**: https://github.com/woocommerce/woocommerce-android/compare/25.6...25.7
+    MARKDOWN
+  end
+  let(:section) { "25.7\n-----\n#{markdown}\n" }
+  let(:options) do
+    {
+      repository: 'woocommerce/woocommerce-android',
+      tag_name: '25.7',
+      target_commitish: 'published-sha',
+      previous_tag: '25.6',
+      configuration_file_path: '.github/developer-release-notes.yml',
+      github_token: 'fake-token'
+    }
+  end
+
+  before do
+    allow(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:`).with('git rev-parse HEAD').and_return('published-sha')
+    allow(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:run).and_return(markdown)
+  end
+
+  def generate(path, **overrides)
+    run_described_fastlane_action(**options, version: '25.7', release_notes_file_path: path, **overrides)
+  end
+
+  it 'forwards the comparison options and requires API errors to fail' do
+    expect(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:run) do |config|
+      expect(config.values).to include(**options, fail_on_error: true)
+      markdown
+    end
+    with_tmp_file(content: original) { |path| generate(path) }
+  end
+
+  it 'keeps the generated Markdown and replaces only the requested version' do
+    with_tmp_file(content: original) do |path|
+      expect(generate(path)).to eq(section)
+      expect(File.read(path)).to eq(header + section + history)
+      expect(Fastlane::Actions::ExtractReleaseNotesForVersionAction.run(version: '25.7', release_notes_file_path: path)).to eq(markdown.chomp(''))
+    end
+  end
+
+  it 'inserts a missing version and is idempotent on subsequent runs' do
+    with_tmp_file(content: header + history) do |path|
+      2.times { generate(path) }
+      expect(File.read(path)).to eq(header + section + history)
+    end
+  end
+
+  it 'preserves a newer empty section when regenerating an older version' do
+    with_tmp_file(content: "25.8\n-----\n\n#{original}") do |path|
+      generate(path)
+      expect(File.read(path)).to eq("25.8\n-----\n\n#{header}#{section}#{history}")
+    end
+  end
+
+  it 'preserves CRLF line endings' do
+    with_tmp_file(content: original.gsub("\n", "\r\n")) do |path|
+      generate(path)
+      expect(File.read(path)).to eq((header + section + history).gsub("\n", "\r\n"))
+    end
+  end
+
+  ["\n", "\r\n"].each do |newline|
+    it "normalizes CRLF Markdown to the file's #{newline.inspect} line endings" do
+      allow(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:run).and_return(markdown.gsub("\n", "\r\n"))
+      with_tmp_file(content: original.gsub("\n", newline)) do |path|
+        generate(path)
+        expect(File.read(path)).to eq((header + section + history).gsub("\n", newline))
+      end
+    end
+  end
+
+  it 'previews the generated section without writing' do
+    with_tmp_file(content: original) do |path|
+      expect(generate(path, dry_run: true)).to eq(section)
+      expect(File.read(path)).to eq(original)
+    end
+  end
+
+  it 'leaves the file untouched when GitHub fails' do
+    allow(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:run).and_raise(Octokit::NotFound)
+    with_tmp_file(content: original) do |path|
+      expect { generate(path) }.to raise_error(Octokit::NotFound)
+      expect(File.read(path)).to eq(original)
+    end
+  end
+
+  it 'rejects an implicit comparison boundary' do
+    with_tmp_file(content: original) do |path|
+      expect { generate(path, previous_tag: nil) }.to raise_error(/explicit previous_tag/)
+      expect(File.read(path)).to eq(original)
+    end
+  end
+
+  it 'rejects an invalid version' do
+    with_tmp_file(content: original) do |path|
+      expect { generate(path, version: "25.7\nInjected") }.to raise_error(/numeric release version/)
+      expect(File.read(path)).to eq(original)
+    end
+  end
+
+  it 'accepts changes to the generated Markdown format without parsing PR entries' do
+    notes = "## Changes\n- Fix checkout (#123) — developer\n\nThanks to our contributors!\n"
+    allow(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:run).and_return(notes)
+    with_tmp_file(content: original) do |path|
+      generate(path)
+      expect(File.read(path)).to eq("#{header}25.7\n-----\n#{notes}\n#{history}")
+    end
+  end
+
+  it 'allows an empty release when all PRs have been excluded' do
+    notes = "**Full Changelog**: https://github.com/woocommerce/woocommerce-android/compare/25.6...25.7\n"
+    allow(Fastlane::Actions::GetPrsBetweenTagsAction).to receive(:run).and_return(notes)
+    with_tmp_file(content: original) do |path|
+      generate(path)
+      expect(File.read(path)).to eq("#{header}25.7\n-----\n#{notes}\n#{history}")
+    end
+  end
+
+  ["Unrecognized file format\n", "25.7\n-----\n\n25.7\n-----\n"].each do |invalid_contents|
+    it "leaves an invalid file untouched: #{invalid_contents.inspect}" do
+      with_tmp_file(content: invalid_contents) do |path|
+        expect { generate(path) }.to raise_error(/No version headings|Duplicate release notes/)
+        expect(File.read(path)).to eq(invalid_contents)
+      end
+    end
+  end
+end
diff --git a/spec/get_prs_between_tags_spec.rb b/spec/get_prs_between_tags_spec.rb
index 0c63fdb2f..6ee5b3ef5 100644
--- a/spec/get_prs_between_tags_spec.rb
+++ b/spec/get_prs_between_tags_spec.rb
@@ -51,7 +51,7 @@ def test_with_params(target_commitish: nil, previous_tag: nil, configuration_fil
 
       allow(client).to receive(:post).with(
         "repos/#{test_repo}/releases/generate-notes",
-        config_file_path: configuration_file_path,
+        configuration_file_path: configuration_file_path,
         previous_tag_name: previous_tag,
         tag_name: test_tag_name,
         target_commitish: target_commitish || test_head_ref
@@ -110,7 +110,7 @@ def test_with_params(target_commitish: nil, previous_tag: nil, configuration_fil
     def stub_failing_api_call(target_commitish: nil, previous_tag: nil, configuration_file_path: nil, error_msg: 'API Failure')
       allow(client).to receive(:post).with(
         "repos/#{test_repo}/releases/generate-notes",
-        config_file_path: configuration_file_path,
+        configuration_file_path: configuration_file_path,
         previous_tag_name: previous_tag,
         tag_name: test_tag_name,
         target_commitish: target_commitish || test_head_ref