When to use iOS device token when sending push notifications through FCM?

Question

I'm confused about the implementation of cloud messaging through FCM. To send an iOS device a remote (push) notification, an iOS device token is needed for APNs. However, a Firebase app doesn't interface with APNs, it interfaces with FCM, which interfaces with APNs. But to send a push notification (or message) to any client through FCM requires an FCM token. Does this mean that the iOS device token is not needed for a Firebase app to send push notifications to iOS devices?

Answer 1

Only an FCM token is required to send a message to a device. There is no Apple-specific data required. Firebase handles the details of each underlying push notification system.