The address destination for Swapped ERC20 token is from a different exchange or wallet. All you need to do before using an ERC20 address on the Swap Tool is make sure that the exchange supports trading of the particular asset you are attempting to receive.
NOTE: Your destination address for where you wish to receive your swapped native asset/token is not from xFutures.io Exchange. This address is where you wish to receive your non-x version of the token, where you wish to receive the actual token and is usually your hardware wallet, MyEtherWallet, Metamask, or other alternative exchange account.
If the conditions described above apply, then you can simply retrieve a deposit address from that other exchange.
For example, with Binance, you can get a deposit address under Funds > Deposits then you can select the asset from the dropdown menu.
When retrieving a token address from another exchange, look for it among the supported assets of the specific platform.
Once the address is located, you can then copy the address (destination address) and paste it back on swap.xfutures.io.
Another option is that you can withdraw the token to a created wallet.