//app.UseMvcWithDefaultRoute();
            app.UseMvc(routes=> {
                // add the new route here.
                routes.MapRoute(name: "areaRoute",
                    template: "{area:exists}/{controller}/{action}",
                    defaults: new { controller = "Home", action = "Index" });

                routes.MapRoute(
                    name: "default",
                    template: "{controller}/{action}/{id?}",
                    defaults: new { controller = "Home", action = "Index" });
            });

    [Area("Admin")]
    public class HomeController: Controller
    {
        public IActionResult Login()
        {
            return View();
        }
    }