Examine source code of lichess-ff

{
  "manifest_version": 2,
  "name": "lichess-ff",
  "version": "0.4.9",
  "description": "Chess traps hints for Lichess",
  "icons": {
    "32": "img/lichess_logo32.png",
    "48": "img/lichess_logo.png",
    "96": "img/lichess_logo96.png"
  },
  "background": {
    "scripts": [
      "libs/jquery-3.5.1.min.js",
      "libs/rxjs.umd.min.js",
      "src/utils.js",
      "src/apiUtils.js",
      "src/background.js"
    ]
  },
  "page_action": {
    "default_icon": "img/lichess_logo.png"
  },
  "web_accessible_resources": [
    "img/*"
  ],
  "permissions": [
    "activeTab",
    "tabs",
    "*://localhost/*",
    "webRequest",
    "storage"
  ],
  "options_ui": {
    "page": "src/options/options.html"
  }
}