To deposit Ripple to your DSX balance you need to use your wallet address and your Destination tag associated with your account. You can find that information in Account -> Balances section.
Click Add XRP. You will be additionally notified that a failure to provide the Destination Tag with your transfer will result in the loss of funds. Accepting these terms will allow you to see your wallet address you should use to transfer XRP to DSX.
Due to the specifics in XRP addressing, Destination tag is the ultimate identifier of the sender. If you fail to enter the Destination Tag correctly, we won't be able to allocate your transfer and credit it to your balance.