Yes, you will be notified about your class 90 mins before the class start time through an app notification. If you’ve registered on the app with your gmail account, all your booked classes will start appearing on your google calendar. 

Set up a time on your calendar for how much in advance you want to get reminded about your class. Turning on Google calendar notification feature also means that you will be auto-subscribed to email notifications on each booking or cancellation. In case you wish to unsubscribe to calendar notifications, you can go to the profile section , click on Class Reminders and turn off “Google Calendar Notifications”