Can customers pay for a subscription with a gift card?

Your customers can easily pay for the initial subscription order with a gift card directly in Shopify Checkout. However, Shopify Checkout will still prompt them to add a credit card to the order, as this credit card will be used to renew the subscription. 
This means that customers can pay for the initial subscription order with a gift card, but subsequent renewals will be processed with a credit card linked to the subscription.