Sending push notification without configuring APNs authentication key

Question

In official firebase documentation it is said that

For FCM specifically, you'll need to upload your APNs authentication key and register for remote notifications.

https://firebase.google.com/docs/cloud-messaging/ios/client

Is it possible to send push notification without configuring a APNs authentication key in firebase console?

If it is not possible then why?

Answer 1

It's not possible, since the APNs says it in the very name, Push Notification Services, if you don't configure that then you'll be sending your notifications to nothing, I understand that's how your project will know were it's receiving the notifications from, so it can process them and sending to your app.