Examine source code of Passenger

{
  "manifest_version": 3,
  "name": "Passenger",
  "browser_specific_settings": {
    "gecko": {
      "id": "passenger@tpsoft.org"
    }
  },
  "author": "TPsoft.org",
  "default_locale": "en",
  "description": "__MSG_ExtensionExtraShortDescription__",
  "version": "0.5",
  "icons": {
    "64": "images/passenger-icon5.64.png",
    "128": "images/passenger-icon5.128.png"
  },
  "permissions": [
    "alarms",
    "contextMenus",
    "cookies",
    "idle",
    "privacy",
    "storage",
    "tabs",
    "unlimitedStorage",
    "webRequest"
  ],
  "host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "bower_components/crypto-js/crypto-js.js",
      "lib/Passenger.js",
      "PassengerBackground.js"
    ],
    "type": "classic"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "lib/jquery-3.7.1.min.js",
        "bower_components/crypto-js/crypto-js.js",
        "lib/Passenger.js",
        "lib/fifoLocalStorage.js",
        "contentScript/PassengerContent.js"
      ],
      "css": [
        "css/PassengerCommon.css",
        "contentScript/PassengerContent.css"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "action": {
    "default_icon": {
      "64": "images/passenger-icon5.64.png",
      "128": "images/passenger-icon5.128.png"
    },
    "default_popup": "browserAction/index.html",
    "default_title": "Passenger"
  },
  "options_ui": {
    "page": "options/index.html"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "images/*",
        "fonts/*"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ]
}