Can't refresh oaut access token

We are trying to refresh our oaut access token by making a post request, using php, to this url:{ACCESS_TOKEN}
As a request header we followed the documentation and used “authorizathion” : “Basic base64(Client_Id:Client_secret)”

The error we ran into is:
{“reason”:“Internal Error”,“error”:“invalid_request”}

This is a screenshot of the code we used

Hey @acquistiict,

You need to refresh using the refresh token like this:{REFRESH_TOKEN}

Let me know if that works!