What has to be in place for a paid online order to become a ticket at the right counter without anybody noticing it arrived.
An online order is automatic when nobody has to look at a screen for it to become a ticket. The guest pays, the order lands at the counter that makes it, and the printer at that counter produces a ticket with the guest's name on it. Nobody re-types the order, nobody reads it out over a rail, and nobody has to be standing in front of a tablet at the moment it arrives.
That last part is the whole test. A system where a paid order appears in a list somebody has to notice is not automatic, it is a list. The person who was meant to be watching it is serving a guest, and orders stack up unseen behind a screen that has gone to sleep. Paper does not need to be watched, which is the only reason any of this works on a busy night.
Three things, all of them set up before the first guest arrives. The menu has to say which counter owns each item, or an order has nowhere to go. Each counter needs one machine that stays awake, plugged in and connected, whose only job is to take the orders addressed to that counter and put them on paper. And the orders have to wait somewhere durable rather than in the memory of whatever is printing them.
That third point is what separates a setup that survives an evening from one that does not. If a printer is out of paper, has its cover up, or is restarting, the order should sit in a queue and print when the counter is ready again - in the order it arrived, once each. Nothing about that recovery should need a person to retype a thing, and a problem at one counter should never hold up another.
Automatic has one weakness, and it is the obvious one: when nothing needs a person, nobody is watching. So the system has to speak up for itself. Something should be checking each counter continuously and telling a named human the moment that counter stops printing, with the counter's name in the message. The failures worth planning for are physical and they all happen at the counter - no paper or an open cover, power pulled out, a lost network connection. Spare rolls belong at the counter, not in an office.
Before you open, place one real order against each counter and let it print untouched, then turn one printer off, place another order, turn it back on and watch that ticket arrive on its own. One test per counter, not one test for the venue. If both of those pass everywhere, the counters are genuinely running themselves, and the only thing left for staff to do is make the order and call the name.