All charge actions are done using your existing payment gateway and First Data.
To redeem or reload the First Data card, simply use your payment gateway API and the First Data card number that was returned at checkout.
Do not attempt to interact directly with the Affirm API for charges that were created. All charge interactions must be done through First Data.
Furthermore, the state of the Affirm charge as it appears in the Merchant Dashboard will not always reflect the charge state on the card network. For example, a refunded charge may not show as refunded on Affirm's side for up to 24 hours. Please refer to our merchant resources for customer-facing teams to help explain the relationship between charge actions on the gift card network (processed by the merchant) and the charge state in Affirm's system (visible to the customer).