Web API Helper Code

Hi, I am trying to connect dynamics 365 on premise with the official helper code in asp.net web api project. however, it stopped in the authentication part without error message, I tried the same code in console program project, and it worked fine. did I miss some configurations? I attached the code snippet where it stops in the authentication.cs. Please advise

  AuthenticationParameters ap = AuthenticationParameters.CreateFromResourceUrlAsync(
                    new Uri(serviceUrl + "api/data/")).Result;

                return ap.Authority;