Добавьте файлы проекта.

Yuna.OauthServer/Endpoints/Auth/AuthEndpoints.cs

@@ -0,0 +1,19 @@
+using Microsoft.AspNetCore.Mvc;
+using Yuna.OauthServer.Endpoints.Auth.DTO;
+
+namespace Yuna.OauthServer.Endpoints.Auth
+{
+    public class AuthEndpoints
+    {
+        public void Define(WebApplication app)
+        {
+            app.MapGet("oauth/auth", Authorize)
+        }
+
+        public IResult Authorize([AsParameters] AuthRequest request)
+        {
+
+        }
+
+    }
+}