post https://api.dev.givecard.dev/api/v1/cards/issueVirtual
Creates and delivers virtual cards to the given email addresses. This endpoint returns the count and external IDs of cards ordered, and the card order.
Optionally pass in an amount to load funds onto the card upon order.
Optionally pass in a merchant rule ID to apply a spend rule to the cards upon order. To create a spend rule and limit where cardholders can use funds, refer to Create Merchant Rule.