Examine source code of Trocker

{
  "background": {
    "type": "module",
    "scripts": [
      "service-worker.js"
    ]
  },
  "action": {
    "default_icon": {
      "16": "img/icon_16.png",
      "48": "img/icon_48.png",
      "128": "img/icon_128.png"
    }
  },
  "content_scripts": [
    {
      "all_frames": false,
      "js": [
        "trocker.js"
      ],
      "matches": [
        "*://mail.google.com/*",
        "*://inbox.google.com/*",
        "*://*.mail.live.com/*",
        "*://*.outlook.live.com/*",
        "*://*.outlook.office365.com/*",
        "*://*.outlook.office.com/*",
        "*://*.outlook.cloud.microsoft/*",
        "*://*.mail.yahoo.com/*"
      ],
      "match_about_blank": true,
      "run_at": "document_end"
    }
  ],
  "default_locale": "en",
  "description": "__MSG_extension_description__",
  "homepage_url": "https://trockerapp.github.io",
  "icons": {
    "16": "img/icon_16.png",
    "48": "img/icon_48.png",
    "128": "img/icon_128.png"
  },
  "manifest_version": 3,
  "name": "__MSG_extension_name__",
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "permissions": [
    "declarativeNetRequest",
    "declarativeNetRequestFeedback",
    "declarativeNetRequestWithHostAccess",
    "storage"
  ],
  "optional_permissions": [],
  "host_permissions": [
    "<all_urls>",
    "*://*.google.com/*",
    "*://*.live.com/*",
    "*://*.googleusercontent.com/*"
  ],
  "short_name": "__MSG_extension_name__",
  "version": "3.4.1",
  "web_accessible_resources": [
    {
      "resources": [
        "img/tl.png",
        "img/td.png",
        "img/tr.png",
        "img/tlc.png",
        "img/tracked.png",
        "img/trackedr.png",
        "bypasser.html",
        "updated.html"
      ],
      "matches": [
        "*://*/*"
      ]
    }
  ],
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "DNR_proxy_rules",
        "enabled": true,
        "path": "data/DNR_proxy_rules.json"
      },
      {
        "id": "DNR_bypass_redirects",
        "enabled": true,
        "path": "data/DNR_bypass_redirects.json"
      }
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4f6dcd29-0a10-4235-a473-211111e98604}",
      "strict_min_version": "109.0"
    }
  }
}