Get_calendar returns "request is not authorized"

I am using the alpaca-trade-api for Python in version 1.4.1. I am a paid subscriber.
I am experiencing this issue:

HTTPError: 401 Client Error: Unauthorized for url:

Other endpoints work fine, I can query them using the same instance of the REST api. Anyone?

The reason for this was passing a wrong url into the function - it works fine passing the paper trading url. More info in the readme of the github repo.