// Program.cs
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRazorPages();

var app = builder.Build();
app.UseStaticFiles();
app.MapRazorPages();

// Map the RichTextBox upload endpoint
app.MapRichTextBoxUploads();

app.Run();

// Razor Page
<richtextbox
    name="uploadEndpointEditor"
    toolbar="default"
    height="300px" />