If customers opt to cancel the payment on the BoxPay checkout page, they will be redirected to the URL specified in the frontendBackUrl field during the creation of the checkout session using the Create Checkout Session API. On that page, you can either take them back to their shopping cart or display a ‘Order Cancelled’ message based on your business case.

It’s important to note that this scenario differs from the payment failed case. In the case of payment failure, the customer intended to make a payment, but it was unsuccessful due to business or technical issues.