401 Unauthorised - POST REST API for refresh token

Hi all   Back again – stuck with the next error.  I am trying to get a new valid access_token, using an earlier received refresh_token. Flow works fine in Postman, but not in Mendix. I get 401 – unauthorised, but when I make the call, with the same refreshtoken in Postman, it works like a charm.   Postman: Mendix call:   I have tried several variants with the urlEncode() function. None of them works …   Any ideas?    
1 answers

Looks like you're putting a string in the request template instead of a json object. Braces and quotes around attributes and values are missing. You could have Mendix take care of it by creating a non persistable object with attributes and values as needed, exporting it to json and use that string as the one parameter in the template.