Добавил роуты до контроллер? чтобы получить доступы через постман

Payments/Payment.WebApi/Controllers/SupplierController.cs

@@ -5,6 +5,7 @@ using Payment.WebApi.Repositories.Interfaces;
 namespace Payment.WebApi.Controllers;
 
 [ApiController]
+[Route("Suppliers/[action]")]
 public class SupplierController : Controller
 {
     private readonly ISupplierRepository _supplierRepository;
@@ -14,6 +15,8 @@ public class SupplierController : Controller
         _supplierRepository = supplierRepository;
     }
 
+    [HttpGet]
+    [ActionName("GetAll")]
     public ActionResult<List<Supplier>> GetAll()
     {
         try

Payments/Payment.WebApi/Controllers/UserController.cs

@@ -5,6 +5,7 @@ using Payment.WebApi.Repositories.Interfaces;
 namespace Payment.WebApi.Controllers;
 
 [ApiController]
+[Route("Users/[action]")]
 public class UserController : Controller
 {
     private readonly IUserRepository _userRepository;
@@ -14,6 +15,8 @@ public class UserController : Controller
         _userRepository = userRepository;
     }
 
+    [HttpGet]
+    [ActionName("GetUser")]
     public ActionResult<User> GetUser(int id)
     {
         try