COD is a special currency, valued at one dollar, and is only used on the Coco website. However, you can still use it easily since its value does not change, and you can exchange it for other currencies for transactions. You can click this link to read more information about COD: https://blog.coco.game/p/cod-the-cocogame-dollar

Click Wallet -> Swap, you can exchange from COD to other currencies without fees and withdraw as usual.