Generally, an order will print based on your prep time. If it is a future order, and your POS prep time is set to 15 minutes, the order will not print until 15 minutes before it is due.
Some of our integrations send the order ready time as the time that their driver will be able to make it to your store, even if that time is longer than your prep time. For instance, if your prep time is 20 minutes, but the ordering platform can't schedule a driver for 60 minutes, they will send in an order ready time of 60 minutes.
Depending on your POS configuration, this may cause the ticket to not show on the KDS or print until 20 minutes (or whatever your prep time is set to be) before the time the driver is to arrive to ensure the food is fresh and hot.