Order/invoice timeout periods are set to 24 hours by default. This means customers have 24 hours before their order/invoice's status gets voided and they'd have to place a new order to make a payment.
That said, 24 hour invoice timeouts can be a burden for sellers whose stock is low or who are being targeted by malicious sellers. This is why we've made it possible to specify a custom invoice timeout period. Here's how:
Go to your SellApp storefront payment settings by clicking here
Scroll down and enter the invoice timeout period (in hours) in the "Void invoices" section, then click 'Save'
Once done, new orders/invoices will be voided after the specified invoice timeout period. If you enter '1' as the value in the above step, orders/invoices will be voided exactly 1 hour after the customer creates the order.