If you're using Lightspeed Retail and a customer wants to redeem their gift card, the only way to accept this payment method is to process it from Lightspeed.
Step 1 - Create the sale from the Lightspeed Register
Step 2 - Apply the gift card payment, and apply the balance to the customers 'account'.
Step 3 - Charge the balance on the customer's accountStep 4 -In the "Lightspeed sales' tab within QuoteMachine invoices, select 'import' on that sale.
Step 4 - You'll now have a partially paid invoice assigned to that customer.