Don't use the "withdraw" option, that requires KYC and only applies to back accounts transfers.

Instead, use "Send", then select the wallet where the bitcoins are from, then send to a Bitcoin address from another wallet or exchanger.
This doesn't need KYC but requires an on-chain transaction fee; however, you can only use your "non-trading wallet(s)" on this.

If the $50 amount is in your "Trading Account", then there's nothing you can do about it but to comply with their demands since it's in the custodial part of their service.