Program_Startup.cs

var host = new WebHostBuilder()
    [...]
    .ConfigureServices(services =>
    {
        [...]

        services.AddNodeServices(options => {
            if ("development".Equals(environment, StringComparison.OrdinalIgnoreCase))
            {
                options.LaunchWithDebugging = true;
                options.DebuggingPort = 5858;
            }
            options.NodeInstanceOutputLogger = loggerFactory.CreateLogger("Node Console Logger");
        });

        [...]
    }
    .Configure(app =>
    {
        var env = app.ApplicationServices.GetService<IHostingEnvironment>();
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseWebpackDevMiddleware(new WebpackDevMiddlewareOptions
            {
                HotModuleReplacement = true,
                HotModuleReplacementServerPort = 6000,
                ReactHotModuleReplacement = true,

            });
        }
        
        [...]
        
        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");

            routes.MapSpaFallbackRoute(
                name: "spa-fallback",
                defaults: new { controller = "Home", action = "Index" });
        });
    }
               
    [...]
    .Build();