The video below will show you how to add a license to the Cloud Zoo:

Cloud Zoo uses port 443 (HTTPS) exclusively, and contacts https://cloudzoo.rhino3d.com and https://accounts.rhino3d.com . This means that it should not be necessary to add any whitelist entries in general network firewalls (assuming normal web traffic is allowed). Rhino is notified of licence status at localhost:1717 - which is not normally blocked with firewalls but may sometimes be blocked where additional security measures have been placed on a workstation.