Examine source code of Referer By Domain

{
  "manifest_version": 3,
  "name": "Referer By Domain",
  "description": "Control the Referer header per domain. Improve privacy and compatibility with fine-grained rules.",
  "version": "1.0.0",
  "author": "Transfairs",
  "homepage_url": "https://github.com/transfairs/referer-by-domain",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "referer-by-domain@transfairs.de"
    }
  },
  "icons": {
    "16": "icons/gear-16x16.png",
    "32": "icons/gear-32x32.png",
    "48": "icons/gear-48x48.png",
    "128": "icons/gear-128x128.png"
  },
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "src/background/background.js"
    ],
    "type": "module"
  },
  "action": {
    "default_popup": "src/popup/popup.html",
    "default_title": "Referer By Domain",
    "default_icon": {
      "16": "icons/gear-16x16.png",
      "32": "icons/gear-32x32.png",
      "48": "icons/gear-48x48.png",
      "128": "icons/gear-128x128.png"
    }
  },
  "options_ui": {
    "page": "src/options/options.html",
    "open_in_tab": true
  },
  "web_accessible_resources": [
    {
      "resources": [
        "icons/*",
        "src/assets/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}