Whenever you make an exchange, you need to have a sender and a recipient. On FLASHIFT, the recipient address is where you will get the new currency after the swap is done. For example, if you want to receive Ether (ETH), you should enter an ETH wallet address as the recipient, and the exchange service will transfer coins to this address when the swap is finished. In general, the recipient’s wallet address is your own address that the exchange service will send coins to after the exchange is done. Make sure you only enter a wallet address that you can access for sure.