Examine source code of Browsing Time Tracker pro

{
  "manifest_version": 3,
  "name": "Browsing Time Tracker",
  "version": "1.0",
  "description": "Track time spent on each website with visual charts and idle detection",
  "permissions": [
    "tabs",
    "storage",
    "idle",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "browsing-time-tracker@example.com",
      "data_collection_permissions": {
        "required": [
          "websiteActivity"
        ]
      }
    }
  }
}