Problem with getting OAuth Code from API call with Postman

Problem with getting OAuth Code from API call with Postman

Hello,

We are using zohobooks in our .net Web API project. Try to implement OAuth 2.0 with self client registration.
We get an error on Get Authorization Code with api call from code part / post : "Invalid Redirect Uri Redirect URI passed does not match with the one configured"
So can you send details about how to get Authorization Code from API call using Postman ?

Thank you.