Error on trying to create a widget

Hi,

I am using the REST API and trying to create a widget by calling a POST to /widgets

After creating the a new token with all the required permissions, I am still getting a 401 Code error with the following message:

{"message":"You cannot work on behalf of this user","code":"UNAUTHORIZED"}

I also tried using the 'Try it now' functionality in the documentation and still received the same error there as well.

Anyone has tried this call and can help me with this?

Thanks