Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace aggregator_host
{
    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.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();
            services.AddSingleton<IApiKeyRepository, ApiKeyRepository>();
            services.AddAuthentication(o =>
            {
                o.DefaultScheme = ApiKeyAuthenticationScheme.DefaultScheme;
            })
            .AddScheme<ApiKeyAuthenticationOptions, ApiKeyAuthenticationHandler>(ApiKeyAuthenticationScheme.DefaultScheme, o => { });

        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment _/*env*/)
        {
            app.UseHttpsRedirection();

            app.UseRouting();

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

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