If your lesson takes place after 24 hours:
you can go to the lesson page and request to "change date/time" of the lesson or "cancel lesson".
Students and Teachers each have ONE chance of requesting a lesson cancellation.
The lesson will only be canceled or rescheduled when the other party agrees to the request. Otherwise, the lesson will proceed at the originally scheduled time.
When a lesson cancellation request is accepted, the credits of the lesson will be refunded to the Student's wallet.
Can't find the reschedule/cancel button for an upcoming lesson?
If a lesson is about to start within 24 hours, it can NOT be changed to a new time or be canceled.
After any lesson, a "there was a problem" button will be available for both teacher and student to propose rescheduling the lesson or a refund within 72 hrs. Check How can I report a lesson problem?