Invertase: Firebase Cloud Messaging (FCM) with iOS devices

I'm trying to use push notifications on iOS devices with react-native.

I'm using Invertase and I managed to make them work on Android.

The only things I'm doing are: ask for the permission with messaging().requestPermission(); and registering a token with

firebase.messaging().getToken()

I can get a token on both devices. However when sending them with admin.messaging().sendToDevice does display the notification on Android but not on iOS although I don't get any error for both.

What Am I missing? Is there something more to do to handle notifications on the iOS part? Do I have to use zo0r/react-native-push-notification or wix/react-native-notifications?

Could you provide a push notification code example working on iOS with Invertase?