Examine source code of Web Font Detector

{
  "manifest_version": 3,
  "name": "__MSG_extName__",
  "description": "__MSG_extDesc__",
  "version": "1.0.0",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_title": "__MSG_extName__",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "permissions": [
    "activeTab",
    "scripting",
    "downloads"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "font-detector@asusiran.hub",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}