To check if the customer has already used the code, you can check it through Teller.

For how to search for an order, see here:

How you can check the ticket status from the tickets panel.

If in the ticket column the color of the pin is blue, it means that the code has been used (it has been checked-in). If you put your mouse over the blue pin, you will see what time the ticket, checked in.

Possibility to uncheck a ticket.

You have this option, so the ticket can be used again.

How can you uncheck a ticket?

1 - Select the ticket and select "Uncheck ticket"

An attention popup window will appear and will ask for confirmation. Once you confirm it the Uncheck will be completed.

The ticket status will change, the pin color will be green, and the code is ready to be used again.