Could not find any method in the PHP SDK that would generate a new access_token based on the refresh_token. Is there something missing ? How can i do that without doing manual CURL calls?
Looking at the code I would consider the oauth_token method with the respective refresh token grant type.
My knowledge of PHP is little, but that method seems to be calling the expected endpoint for a refresh token request, /oauth/token, so if you pass the expected options for such a request it may do the trick.
I have the same question, did you resolve this?