Examine source code of Travian Overlay

{
  "manifest_version": 3,
  "name": "Travian Overlay",
  "version": "1.0",
  "description": "Overlay dla Traviana – przeliczacz obrony",
  "permissions": [],
  "content_scripts": [
    {
      "matches": [
        "*://*.travian.com/*dorf1.php*"
      ],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "travian-overlay@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}