If you want to use gift cards to manage store credit for returns, you'll need to set up Refund to gift card as a payment type.
In Lightspeed Retail, go to Payment types
2. Click Add payment type
3. Choose Other payment method and click Begin setup
4. Give your new payment type a clear name like Refund to gift card
5. Enter into the Gateway field:
6. Click Save payment type and it will appear in the payment types list