/tests/tools/fixtures/extension-content-script/manifest.json

{
  "manifest_version": 3,
  "name": "Test Extension with Content Script",
  "version": "1.0",
  "permissions": ["tabs", "scripting"],
  "host_permissions": ["<all_urls>"],
  "content_scripts": [
    {
      "matches": ["<all_urls>"],
      "js": ["content.js"],
      "run_at": "document_start",
      "all_frames": true
    }
  ]
}