How Do I Reprint The Last Receipt?
When on a brand new ticket you have the 'Reprint Last' option.

Note: This will disappear once items are added to the current ticket
How Do I Recall A Saved Ticket?
To recall a saved ticket press
while on the POS and choose 'Recall/Reprint'.

You will then be presented with a screen showing open and closed tickets.

To Reopen the ticket press on the desired ticket and choose reopen.