Once a ticket is scanned, you are already considered checked in (see scanning a ticket for more info). if the patron lost their email, do the following:
First, go to the "Orders" tab and search the name of the order that you would like to switch.
*Make sure that the filters are clear so you can find the order that you're looking for.
*The name search only doesn't need a complete name. You can search an order with just partial name.
Once you find your order, click "View Ticket" to see the details of your order
From here there are two paths:
A. Check In All - this will check in every ticket in the order.
B. Check in individual tickets.