According to all of the various instructions, when looking at an App setup within Appcenter I should expect to see a Push option so I can setup the Firebase Server Key. Apparnetly it's meant to be between Analytics and Settings. Nor can I find any discussion about this being a higher service or how to make it visible.
Where do I enter the Firebase Sever Key and configure push notifications now?
Our MBaaS services have been retired you can find more information about that in this blog post: https://devblogs.microsoft.com/appcenter/app-center-mbaas-retirement/
There is also a note in our docs about this: https://learn.microsoft.com/en-us/appcenter/push/