You may see an "Add class to calendar" button when attempting to book a class. Don't worry -- this doesn't mean you've accidentally signed up! Rather, this button appears any time online scheduling is disabled for a class.
What does the "Add to Calendar" button do?
It simply places a reminder on your phone's calendar at the time of the event. It does not actually enroll you in the class. This is primarily used when a business places a class on the schedule but does not accept online signups.