Due to the nature of tickets, attendees are not able to cancel their tickets if they cannot attend the event. According to Peatix's Terms of Service, tickets can be cancelled if organizer agrees to cancel the tickets upon the attendee's request. 

As organizer, please set your own ticket cancellation policy. You are recommended to include the policy in the event description for attendees' references. Please note that it is not possible to modify the refund amount (e.g refund only 50% of the ticket price).

When an attendee requests for ticket cancellation, you will receive the request by message. If you approve the request, please cancel the ticket in Sales List. After cancelling the ticket, the amount paid by attendees (minus cancellation fee if any) will be refunded to attendees through Peatix's payment gateway. 

For more information about ticket cancellation and refund, please refer to the help page How to respond to ticket cancellation request.