Problem requesting Grant Token with C# desktop application

Problem requesting Grant Token with C# desktop application

Greetings,

I'm new Zoho and am looking to use the API via a C# desktop application.  I am following the first steps in the following guidelines to request a Grant Token and subsequently request Access and Refresh Tokens:


I have used the API Console to register a Self Client application as there is no user-interface to be dealt with...just a simple retrieval of data in the background.  

This is the C# code that I am using to fetch the Grant Token, but unfortunately, it's returning HTML code instead of JSON content containing what looks like Grant Token.  Have I missed the mark completely?

Thanks,
Scott

  2. public void GetZohoGrantToken()
  3.         {
  4.             try
  5.             {
  6.                 ServicePointManager.Expect100Continue = true;
  7.                 ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
  8.                 ServicePointManager.DefaultConnectionLimit = 9999;

  10.                 HttpWebRequest GroupsRequest = (HttpWebRequest)WebRequest.Create("https://accounts.zoho.com/oauth/v2/auth?scope=ZohoBooks.fullaccess.all&client_id=1000.993FJS7NKWGHRAPZ71W6IW16GYC1WA&response_type=code&redirect_uri=http://www.zoho.com/books&access_type=offline");

  12.                 GroupsRequest.AllowAutoRedirect = true;
  13.                 GroupsRequest.ContentType = "application/json";
  14.                 GroupsRequest.Accept = "*/*";
  15.                 GroupsRequest.Method = "GET";
  16.                  
  17.                 WebResponse GroupsResponse = GroupsRequest.GetResponse();
  18.                 Stream GroupsDataStream = GroupsResponse.GetResponseStream();
  19.                 StreamReader GroupsDataStreamReader = new StreamReader(GroupsDataStream);
  20.                 string GroupsContentFromServer = GroupsDataStreamReader.ReadToEnd();

  22.                 Console.WriteLine(GroupsContentFromServer);

  24.                 GroupsDataStreamReader.Close();
  25.                 GroupsDataStreamReader = null;
  26.                 GroupsResponse.Close();
  27.                 GroupsResponse = null;
  28.                 GroupsRequest = null;

  30.             }
  31.             catch (Exception ex)
  32.             {
  33.                 Console.WriteLine(ex.InnerException);
  34.             }

  36.         }