Although Huobi Pro does not require you to verify your account, there are certain restrictions if you use an unverified account. Specifically, with unverified accounts you can only withdraw a maximum of one coin amount:
0.1 BTC
0.6 Bitcoin Cash
2.5 Ethereum
5 Litecoin
2500 ripple
If you have an account you can withdraw every day:
200 BTC
200 Bitcoin Cash
2000 Ethereum
5000 Litecoin
4 million ripple
To verify you need a passport photo, then go to Verification to enter verification information. You will need to wait several days for your account to be reviewed and upgraded.