1) Within CellSmart POS, go to Admin Tools / General Settings
2) Select the Credit Card tab. Enable "Use CellSmart POS Credit Card Terminal" and confirm the Pax is the selected machine type
3) Enter your Pax device serial number within the Pax Settings section
Your settings should look similar to the image below.
In order to make a sale using the pax terminal, select credit or debit card as a payment method at the time of checkout.