Default Scheme

[!NOTE] When a single authentication scheme is registered, the authentication scheme is automatically used as the app's default scheme, and it isn't necessary to state the scheme to xref:Microsoft.Extensions.DependencyInjection.AuthenticationServiceCollectionExtensions.AddAuthentication%2A or via xref:Microsoft.AspNetCore.Authentication.AuthenticationOptions. For more information, see xref:security/authentication/index#defaultscheme and the ASP.NET Core announcement (aspnet/Announcements #490).