Discount codes and gift cards
Run a promotion, or sell store credit.
Discounts → New code creates a percentage or fixed-amount code. You can limit total uses and set an expiry; both are enforced at checkout, so a code can never be over-redeemed.
Gift cards issue real store credit. The full code is shown when you create it and can be revealed again later from the eye icon — balances are deducted automatically at checkout.