I figured out what was going on. One need to first change the scope of the authorization for the application. This is how I did it:
From your browser execute:
https://api.instagram.com/oauth/authorize/?client_id=CLIENTID&redirect_uri=REDIRECT-URI&response_type=code&scope=SCOPE
Just need to insert your data for the words in uppercase
Once that is done, the application is authorized for that scope.
As I had already the access token, I did not need to do steps 2 and 3.