Firebase/firebaseProject/firebaseMobile/MauiProgram.cs

using Microsoft.Maui.LifecycleEvents;
using Plugin.Firebase.Auth;
using Plugin.Firebase.Bundled.Platforms.Android;
using Plugin.Firebase.Bundled.Shared;
using Plugin.Firebase.Crashlytics;

namespace firebase;

public static class MauiProgram
{
    public static MauiApp CreateMauiApp()
    {
        var builder = MauiApp.CreateBuilder();
        builder
            .UseMauiApp<App>()
            .RegisterFirebaseServices()
            .ConfigureFonts(fonts =>
            {
                fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
            });

        return builder.Build();
    }

    private static MauiAppBuilder RegisterFirebaseServices(this MauiAppBuilder builder)
    {
        builder.ConfigureLifecycleEvents(events => {
#if IOS
            events.AddiOS(iOS => iOS.FinishedLaunching((app, launchOptions) => {
                CrossFirebase.Initialize(CreateCrossFirebaseSettings());
                return false;
            }));
#else
            events.AddAndroid(android => android.OnCreate((activity, _) =>
                CrossFirebase.Initialize(activity, CreateCrossFirebaseSettings())));
            CrossFirebaseCrashlytics.Current.SetCrashlyticsCollectionEnabled(true);
#endif
        });

        builder.Services.AddSingleton(_ => CrossFirebaseAuth.Current);
        return builder;
    }

    private static CrossFirebaseSettings CreateCrossFirebaseSettings()
    {
        return new CrossFirebaseSettings(
            isAuthEnabled: true,
            isCloudMessagingEnabled: true,
            isAnalyticsEnabled: true);
    }
}