It may happen that a student does not show up to your class. If your student doesn't show up, you can send them a message from within the inbox to see if they will be attending. If we don't hear from the student prior to the class taking place, the payment will still be processed.
In order to try to avoid this, you should always speak to your student from within the inbox prior to the class. In that way you can start building your relationship and they will know that if they cannot make it, they can send you a direct message.