FCM使用JAVA代码使用用户的设备令牌

Question

我正在使用firebase创建聊天应用程序，我想使用Java代码而不是使用Firebase Console向用户发送推送通知。我已成功获取用户的设备令牌。

我尝试使用服务，但我一直收到以下错误。有些人请指导我

  

onResponse：无效（传统）服务器密钥已发送或发件人无权执行请求。

无效（传统）服务器密钥已发送或发件人无权执行请求。

错误401

这是我的代码

public class MyAndroidFirebaseMsgService extends FirebaseMessagingService {
    private static final String TAG = "MyFirebaseMsgService";

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        //Displaying data in log
        //It is optional
        Log.d(TAG, "From: " + remoteMessage.getFrom());
        Log.d(TAG, "Notification Message Body: " + remoteMessage.getNotification().getBody());

        //Calling method to generate notification
        sendNotification(remoteMessage.getNotification().getBody());
    }

    //This method is only generating push notification
    //It is same as we did in earlier posts
    private void sendNotification(String messageBody) {
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent,
                PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("Firebase Push Notification")
                .setContentText(messageBody)
                .setAutoCancel(true)
                .setSound(defaultSoundUri)
                .setContentIntent(pendingIntent);

        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        notificationManager.notify(0, notificationBuilder.build());
    }
}

我已在我的清单中注册了此服务