Here are some of the docs that may help, however they are not very detailed:
https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.spaservices?view=aspnetcore-6.0
https://learn.microsoft.com/en-us/aspnet/core/client-side/spa-services?view=aspnetcore-6.0
Microsoft.AspNetCore.SpaServices Namespace Provides types for hosting
a Single Page Application (SPA).SpaOptions Describes options for hosting a Single
Page Application (SPA).ISpaBuilder Defines a class that provides
mechanisms for configuring the hosting of a Single Page Application
(SPA) and attaching middleware.