An application can generate a checkout page by specifying an order in a CreatePaymentLink request (see Checkout API Overview). The following example request specifies an Order object. For simplicity, the example specifies four ad hoc line items. You can also use catalog items. For more information, see Create Orders.
After receiving the requests, Square creates an order, creates a checkout page, and returns the order_id and URL to the checkout page in the response. The following is an example response: