This project was uploaded to work in conjunction with my Angular Material Project: https://github.com/ChristianGalvez23/angular-material-example.git
If you need to change for any reason the URL that is going to connect with this API RESTful, you have to goto the Startup class and change:
app.UseCors (builder =>
builder.WithOrigins (**"http://localhost:4200"**)
.AllowAnyHeader ()
.AllowAnyMethod ()
);