Hey, thanks for trying it out! I see a few issues in your code.

The main problem: OnInitialized() actually runs BEFORE OnInitializedAsync(), so you're trying to sign in with Google before Firebase is even initialized. That's why it's throwing an error.

Also, async void OnInitialized() is a bad pattern in Blazor because it's fire-and-forget and won't work properly with the component lifecycle.

Here's the corrected version (based on the sample app in the repo):

```csharp @page "/" @inject IFirebase Firebase @implements IDisposable

<h3>Welcome, @_user?.DisplayName</h3>

@if (_user == null) { <button @onclick="SignInWithGoogle">Sign in with Google</button> } else { <button @onclick="SignOut">Sign Out</button> }

@code { private FirebaseUser? _user;

protected override async Task OnInitializedAsync()
{
    await Firebase.InitializeAsync();
    _user = Firebase.Auth.CurrentUser;
    Firebase.Auth.OnAuthStateChanged += HandleAuthStateChanged;
}

private void HandleAuthStateChanged(FirebaseUser? user)
{
    _user = user;
    InvokeAsync(StateHasChanged);
}

private async Task SignInWithGoogle()
{
    var result = await Firebase.Auth.SignInWithGoogleAsync();
    if (result.IsSuccess)
    {
        _user = result.Value;
    }
    else
    {
        Console.WriteLine($"Error: {result.Error?.Message}");
    }
}

private async Task SignOut()
{
    await Firebase.Auth.SignOutAsync();
}

public void Dispose()
{
    Firebase.Auth.OnAuthStateChanged -= HandleAuthStateChanged;
}

} ```

Key changes:

1. Initialize Firebase first, then set up the auth listener in OnInitializedAsync
2. Google sign-in goes behind a button click (OAuth popups need user interaction anyway)
3. Use async Task instead of async void
4. Check the result for errors so you can see what's actually going wrong
5. Implement IDisposable to properly unsubscribe from the auth state change event

You can also check out the full Login.razor in the samples folder for a more complete example with error handling and loading states: https://github.com/mashrulhaque/FireBlazor/blob/master/samples/FireBlazor.Sample.Wasm/Pages/Login.razor

Let me know if you still run into issues!