Flutter - APNS token has not been set yet. Please ensure the APNS token is available by calling getAPNSToken()

Question

While calling the subscribeToTopic method in iOS, this APNS token exception is coming. I have followed the documentation. I have used the Flutterfire configure command for configuring the Flutter project.

But this error is coming. Anyone know why this error is coming and how to resolve it?

I haven't called the getAPNSToken() method in the code.

Is it needed to initiate this method before calling subscribeToTopic method?

Note: We are not using tokens to send notifications to particular users. We are using the topic to send notifications. So I'm not calling the getToken and getAPNSToken methods.

1970-01-02 04:49:38.216263+0300 Runner[675:161670] flutter: [firebase_messaging/apns-token-not-set] APNS token has not been set yet. Please ensure the APNS token is available by calling `getAPNSToken()`.
1970-01-02 04:49:38.216725+0300 Runner[675:161670] flutter: #0      MethodChannelFirebaseMessaging._APNSTokenCheck (package:firebase_messaging_platform_interface/src/method_channel/method_channel_messaging.dart:138:9)
<asynchronous suspension>
#1      MethodChannelFirebaseMessaging.subscribeToTopic (package:firebase_messaging_platform_interface/src/method_channel/method_channel_messaging.dart:390:5)
<asynchronous suspension>
#2      PushNotificationService.subscribeUserToFirebase (package:team/src/common/notification/firebase/push_notification.dart:70:7)
<asynchronous suspension>
#3      userAPI (package:team/src/features/master_data/application/master_data_providers.dart:116:5)
<asynchronous suspension>
#4      FutureHandlerProviderElementMixin.handleFuture.<anonymous closure>.<anonymous closure> (package:riverpod/src/async_notifier/base.dart:337:9)
<asynchronous suspension>

Answer 1

As per documentation an APNS token needs to be available before calling subscribeToTopic method.

So on the iOS platform, if apnsToken is not available, we have added a delay. After a delay, if we are calling getAPNSToken, it is getting a token. so we can call the subscribeToTopic method.

Answer Reference: Github Issue Comment

  if (Platform.isIOS) {
    String? apnsToken = await _firebaseMessaging.getAPNSToken();
    if (apnsToken != null) {
      await _firebaseMessaging.subscribeToTopic(personID);
    } else {
      await Future<void>.delayed(
        const Duration(
          seconds: 3,
        ),
      );
      apnsToken = await _firebaseMessaging.getAPNSToken();
      if (apnsToken != null) {
        await _firebaseMessaging.subscribeToTopic(personID);
      }
    }
  } else {
    await _firebaseMessaging.subscribeToTopic(personID);
  }