Ionic native Push IOS subscribe to topic

Hi,

how is it possible to subscribe to a topic for remote push on iOS using ionic-native Push module?
I have simple push using DEVICE TOKEN working, certificates etc. all working fine.
But I want to subscribe the devices to topics and send a notification to all devices within a topic,
without manually keeping track of the device tokens.
This is working on Android (also with ionic-native Push).
Any samples on how to perform this? Maybe also how to send the push notification to the APNS service?

Thanks.

What service are you using to send pushes?
What exactly do you mean by “Ionic native Push”?
How do you do it on Android?

I use Ionic Native Push which is based on Cordova phonegap-plugin-push.
On Android I have exactly the same code (on mobile).
I send the messages through the Firebase Cloud Messaging Console and the APNS equivalent.

Code in you app should be identical for Android and iOS.

I am facing issue with IOS . <FIRMessaging/WARNING> Failed to subscribe to topic Error Domain=com.google.fcm Code=5 “(null)”