I am trying to use the square API, using the Ruby gem, to create an order which is sent to an ipad, used as a POS device, and then printed as an ticket and paid for in person. However, there seems to be no ticket API, and orders don’t get send to the POS device until they are paid for. I have tested it, and orders I create simply never arrive at the POS device. How do I do this using the square API?
At this time only orders that are fully paid for will push to the POS. Once an order pushes to the POS you can configure the setting on the device to automatically print. 
In that case, what is the process to create an order using the API and pay it on a POS device?
At this time creating an order via the API and paying for it at the POS isn’t currently available. We hope to have more for you in the future.