[ANDROID] Firebase Crashlytics build ID is missing

Question

Hi,
I need to add the support to firebase Crashlytics to my Xamarin.forms app.

For iOS it seems to work but on Android doesn't.

I need to have multiple json config files so I used this code to load the configuration:

            FirebaseOptions options = new FirebaseOptions.Builder()  
                        .SetApplicationId(applicationId)  
                        .SetApiKey(apiKey)  
                        .SetGcmSenderId(gcmSenderId)  
                        .SetProjectId(projectId)  
                        .SetStorageBucket(storageBucket)  
                        //.SetGaTrackingId("")  
                        .Build();  
  
            FirebaseApp.InitializeApp(this, options);  

but after I have added the Firebase Crashlytics nuget pack, this error is triggered:

How can I solve this?

Also, there is an update guide to use Firebase in a Xamarin Forms application?
I have found only very old post to do so, but all with some older version of Firebase NuGet packages (ex. they use fabric or an old namespace).

Thank you!