Only silver coins and gold coins can be traded on the exchange. You can buy other people's silver coins with gold coins or sell your own silver coins.

You can open the lower right corner of your backpack to check your credit card. Vouchers are equivalent to gold coins, but you can only buy things in shopping malls, not in exchanges.

Coupons are things that can be discounted (many things are not allowed, only things like fashion can be used).

Golden Apple receives prepaid vouchers and coupons, and double-click to recharge the credit card.