{
    "status": "failed",
    "error": {
        "error": {
            "code": 404,
            "message": "Requested entity was not found.",
            "status": "NOT_FOUND",
            "details": [
                {
                    "@type": "type.googleapis.com\/google.firebase.fcm.v1.FcmError",
                    "errorCode": "UNREGISTERED"
                }
            ]
        }
    }
}