How do I provide refunds for my users?

We had to cancel an event that people had already paid for, and wanted to know if it was possible to provide a refund.

If you are talking about this form, I see that you have been using "Square" in your form. You can make refunds to your users in your Square account panel. I would like to recommend you to check these user guides for further details about Square refunds:

Square: Refund Overview

Square: Process Refunds