You can check this by going to the URL where the barcode of the purchased gift coupon is displayed.
If the product has been exchanged, the gift coupon will be displayed as shown below.
Since some products (such as monetary coupons) can be used bit by bit, the barcode for such products will continue to be displayed even after being used. For example, in the case of an OUTBACK 50,000 KRW coupon, the barcode will be displayed continuously since the balance after use will be saved for use within the validity period of the gift coupon.