Specify base URL for Angular ClientApp served from ASP.NET Core WebApi

I've created an ASP.NET Core project which serves an Angular app using services.AddSpaStaticFiles(), app.UseSpaStaticFiles(), app.UseSpa(), etc.

But it serves the application directly from http://localhost:1234, while I want to serve it from http://localhost:1234/angular/MyAngularApp1/, while I want to use http://localhost:1234/ for an API controller.

How can I achieve that?

from Specify base URL for Angular ClientApp served from ASP.NET Core WebApi