Examine source code of TransferClock

{
  "manifest_version": 3,
  "name": "TransferClock",
  "version": "1.0.0",
  "description": "Estimate file transfer time from a file size and connection speed, then compare common speed scenarios.",
  "icons": {
    "48": "assets/icon.svg",
    "96": "assets/icon.svg"
  },
  "action": {
    "default_title": "Open TransferClock",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "48": "assets/icon.svg",
      "96": "assets/icon.svg"
    }
  },
  "permissions": [
    "clipboardWrite"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "transferclock@example.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}