ASPNetCore/TestAppRuna/Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using TestAppRuna.Data;
using TestAppRuna.Entities;
using TestAppRuna.Services;

namespace TestAppRuna
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
            services.AddRazorPages();
            services.AddServerSideBlazor();
            services.AddSingleton<WeatherForecastService>();

            services.AddScoped<IMathService, MathService>();
            services.AddScoped<ICartService, CartService>();
            services.Configure<AppSettings>(Configuration);
            services.AddScoped<AppSettings>(di => di.GetRequiredService<IOptionsMonitor<AppSettings>>().CurrentValue);

            services.AddDbContext<ShopDbContext>(options =>
            {
                options.UseSqlite(Configuration.GetConnectionString("ShopDB"));
            });

            services.AddAuthentication()
                .AddJwtBearer("nanaoaccounts", options =>
                 {
                     options.Authority = "https://accounts.nanao.moe/auth/realms/staging";
                     options.Audience = "testappruna";
                 }  
                );
            services.AddCors(options => {
                options.AddPolicy("BelajarNextJS", policy => {
                    policy.WithOrigins("http://localhost:3000")
                    .AllowAnyHeader()
                    .AllowAnyMethod();
                });	
            });
            services.AddSwaggerDocument(settings => {
            });
        }

        // 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())
            {
                using (var scope = app.ApplicationServices.CreateScope())
                {
                    var db = scope.ServiceProvider.GetRequiredService<ShopDbContext>();
                    db.Database.EnsureCreated();
                }
            }
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
            }
            app.UseStaticFiles();

            app.UseOpenApi(settings => {
                settings.DocumentName =  "v1";
                settings.Path = "/swagger/v1/swagger.json";
            });

            app.UseSwaggerUi3(settings =>
            {
                settings.DocumentTitle = "TestAppRuna";
                settings.DocumentPath = "/swagger/v1/swagger.json";
            });

            app.UseRouting();

            app.UseAuthentication();
            app.UseAuthorization();

            app.UseCors("BelajarNextJS");

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapDefaultControllerRoute();
                endpoints.MapBlazorHub();
                endpoints.MapFallbackToPage("/_Host");
            });
        }
    }
}