Hello! Graphical designers are available only if you have a subscription. You can see the information of the subscription in CUBA - Subscription Information.
Normally, if you have no commercial subscription, Studio requests a trial subscription from our server and offers it to you. If you didn’t see any notifications about it, and CUBA > Subscription Info window does not allow you to get a trial, please write to info@cuba-platform.com and we will try to help you.