Examine source code of Font Preview Tool

{
  "manifest_version": 2,
  "name": "Font Preview Tool",
  "version": "1.0",
  "description": "Preview text in different Google Fonts",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "clipboardWrite"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "fontpreview-y9n2k5v8@webutils.org",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}