What is the 'Sandbox / staging' tick for on the delivery app card?

For trying the connection before real customers can order. Some apps give you a test account with its own keys, and ticking Sandbox tells us to talk to that test side rather than the live one. Everything behaves the same way, the orders just are not real. Untick it and connect again with your live keys when you are ready. The Orders from delivery apps tab in the docs mentions it in the connect guide.