Depop Wallet is our own payments platform which was offered to some UK users between November 2015 and October 2016. To streamline and improve our payments experience, we have now moved all sellers away from Depop Wallet. You will need to connect your PayPal account to Depop to sell and get paid. To do this go to Profile > Settings > PayPal.
If you have any money remaining in your Wallet, you'll see an option in the app called Wallet (Profile > Wallet). This is where you manage your money. Once you've cashed out all your money, your Wallet will be closed for good.