I'm developing an application that works on the iPhone through the xamarin.ios with firebase backend. I want Push Notifications FCM Firebase, but I couldn't, I want that code in AppDelegate.cs
To implement Push Notifications firebase with xamarin.ios in C#, you can have a try with Xamarin.Firebase.iOS.CloudMessaging.
And there are detailed steps about setting-up-a-firebase-cloud-messaging-client-app-on-ios there.
Code example in AppDelegate
and Sample project
are also available.
Additional, here is document about creating push notification certificates and settings in iOS app.