While you are in an open session on a register, find the Gift Card (which is currently black) and select it.  Ignore the fact that it says $50, you will be prompted for the amount.

After you select the gift card, you will be presented with the Generate a Gift Card box. Before you scan the TSQ Gift Card, select the Gift Card Code box so it focuses on receiving the code from the barcode scanner (like the box on the right). Anytime you are presented with a box like this, you should always select the field you want to start typing in.

First, scan in the barcode off the TSQ gift card in the "Gift Card Code" field.  Second, type the amount the gift card is to be in the "Amount of the gift card" field.  Then Hit Confirm.

Gift card will show in the register with the last 4 digits of the card showing.  Finishing processing the sale as normal.