关于 c#：在使用 ASP.NET Core 3.0 首次加载之前，通过授权服务器保护 SPA 的正确方法是什么？

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(
                Configuration.GetConnectionString("DefaultConnection")));

        services.AddDefaultIdentity<ApplicationUser>()
            .AddEntityFrameworkStores<ApplicationDbContext>();

        services.AddIdentityServer()
            .AddApiAuthorization<ApplicationUser, ApplicationDbContext>();

        services.AddAuthentication()
            .AddIdentityServerJwt();
        services.AddControllersWithViews();
        services.AddRazorPages();
        // In production, the Angular files will be served from this directory
        services.AddSpaStaticFiles(configuration =>
        {
            configuration.RootPath ="ClientApp/dist";
        });
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        if (!env.IsDevelopment())
        {
            app.UseSpaStaticFiles();
        }

        app.UseRouting();

        app.UseAuthentication();
        app.UseIdentityServer();
        app.UseAuthorization();
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllerRoute(
                name:"default",
                pattern:"{controller}/{action=Index}/{id?}");
            endpoints.MapRazorPages();
        });

        app.Use(async (context, next) =>
        {
            if (!context.User.Identity.IsAuthenticated)
            {
                await context.ChallengeAsync("Identity.Application");
            }
            else
            {
                await next();
            }
        });

        app.UseSpa(spa =>
        {
            // To learn more about options for serving an Angular SPA from ASP.NET Core,
            // see https://go.microsoft.com/fwlink/?linkid=864501

            spa.Options.SourcePath ="ClientApp";

            if (env.IsDevelopment())
            {
                spa.UseAngularCliServer(npmScript:"start");
            }
        });
    }
}