Coupon that is basically like a gift card taxable?

Sorry for the bad Google Translate image but this was basically a 10,000 KRW "coupon" (it uses that word) that I won on some Instagram event lottery thing the company as doing. I know usually a coupon isn't taxable and if you have to spend money to "get" money, it's like a rebate and not taxable AFAIK, but this doesn't seem to have any minimum spend and I guess you wouldn't need to spend money to use it (if you were able to find something 10,000 KRW or less).

 

It only has a one-time use and any leftover value is forfeited. I'm thinking it's more like a won a gift card (or similar) in the form of a coupon code so I'd imagine I should report it?

 

Thanks.

 

(Coupon was already used so not worried about the code in the image)

 

coupang eats.jpg