Blazor in WPF, isolation CSS not created

I have followed the steps here to create a WPF Blazor application using ASP.Net Core 6:

https://learn.microsoft.com/en-us/aspnet/core/blazor/hybrid/tutorials/wpf?view=aspnetcore-8.0

However I called my app Sppro Designer

I tested the app name by using this code:

        string projectName = Assembly.GetExecutingAssembly().GetName().Name;

My problem is when I create a razor page, with razor.css file ie (page.razor.css) an isolation css file is not being created.

In index.html I have:

<link href="Sppro_Designer.styles.css" rel="stylesheet" />/* Trying both to be sure */<link href="Sppro Designer.styles.css" rel="stylesheet" />

Both files are coming back as 404.

I have been looking around some post say things along these lines

 var builder = WebApplication.CreateBuilder(args); builder.WebHost.UseWebRoot("wwwroot").UseStaticWebAssets();

however I dont have a builder, or an App, as my services are generated in mainwindow.xaml.cs (remember this is a WPF app)