Push Notifications with FireBase in Xamarin Forms for iOS

I have a Xamarin Forms project for iOS to which I want to sent push notifications using FireBase. I have read lots of documentation and followed it step by step. Still, I'm not able to receive notifications on my device. I need someone who has already achieved doing this and can help me set up a working project (just an app with the standard screen which can receive notifications).

Screenshots and further explanation are below. The assignment has to be executed via TeamViewer and will only be paid if you deliver us a working setup.

Kind Regards
Gilles