在应用程序外部单击时，firebase通知会打开另一个活动

Question

我的问题是我想显示一个firebase通知，该通知是单击时重定向到特定活动的。

在显示应用程序的情况下单击该按钮即可使用。 但是，当应用程序关闭并单击通知时，它仅打开MainActivity，就像通知仅启动应用程序一样。 如何使通知打开该特定活动？ 我的showNotification方法是：

    private void showNotification(String title, String content) {
    NotificationManager mNotificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

    Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {

        NotificationChannel channel = new NotificationChannel("default",
                "YOUR_CHANNEL_NAME",
                NotificationManager.IMPORTANCE_DEFAULT);

        channel.setDescription("YOUR_NOTIFICATION_CHANNEL_DISCRIPTION");

        if (mNotificationManager != null)
            mNotificationManager.createNotificationChannel(channel);
    }

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext(), "default")
            .setSmallIcon(R.mipmap.ic_launcher) // notification icon
            .setContentTitle(title) // title for notification
            .setContentText(content)// message for notification
            .setSound(defaultSoundUri) // set alarm sound for notification
            .setAutoCancel(true); // clear notification after click

    Intent intent = new Intent(getApplicationContext(), CouponsActivity.class);
    PendingIntent pi = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
    mBuilder.setContentIntent(pi);

    if (mNotificationManager != null)
        mNotificationManager.notify(0, mBuilder.build());
}