Has anyone implemented OAuth authentication for a Connect-REST with grant type - Authorization Code?

I am trying to implement that but encountering an error saying - "Could not acquire fresh access token" 

I have provided all the information 

1. Client ID
2. Client Secret
3. Scope
4. Authorization Code Endpoint
5. Access Token Endpoint
6. Redirect URL Endpoint
7. Auth Scheme as Client secret
8. Method as POST and
9. Send token as - Authorization header

Note that I have not added any parameters in the 2 endpoints (Auth Code Endpoint and Access Token Endpoint). I am expecting Pega to automatically add them to the endpoints as I have provided them separately.

Am I missing something? Do I need to still add them as parameters in the end point?

The basic issue looking at the tracer I see is that there is no entry in the dataschema.pr_data_token table where "pygranttype" = ? and "pyscope" = ? and "pyclientid" = ? and "pyuseridentifier" = ? 

Urgent help needed! 

Thanks in advance.

Tanay