Startup.cs

using Board.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using System.Text.Encodings.Web;
using System.Text.Unicode;

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

        public IConfiguration Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {
            services.Configure<CookiePolicyOptions>(options =>
            {
                options.CheckConsentNeeded = context => false;
                options.MinimumSameSitePolicy = SameSiteMode.None;
            });

            services.AddSingleton(
                HtmlEncoder.Create(
                    UnicodeRanges.BasicLatin,
                    UnicodeRanges.CjkUnifiedIdeographs));

            services.AddOptions<BoardOptions>().Bind(Configuration.GetSection("Board"));

            services.AddHostedService<DataService>();
            services.AddControllersWithViews()
                .AddMvcOptions(options => options.Filters.Add<BasicAuthenticationFilter>());
            services.AddSingleton<AuthorizationService>();
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            app.UseDeveloperExceptionPage();
            app.UseStaticFiles();
            app.UseCookiePolicy();

            app.UseRouting();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}