Examine source code of Duplicate Tab Finder

{
  "manifest_version": 3,
  "name": "Duplicate Tab Finder",
  "version": "1.0",
  "description": "Duplicate Tab Finder: Find and close duplicate tabs",
  "action": {
    "default_popup": "popup.html",
    "default_icon": "duplicate_tab_finder.png"
  },
  "icons": {
    "128": "duplicate_tab_finder.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "PhilGreaney27091975ltjk@hotmail.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}