I'm trying to get the refresh code using the authorization code as below
https://api.amazon.com/auth/o2/token?grant_type=authorization_code&code={}&client_id={}&client_secret={}&redirect_uri=https%3A%2F%2Fwww.test.com%2Fp%2Faccesstoken.html
However I got below error
{"error_description":"Malformed request","error":"invalid_request"}