Visit Huobi Futures https://futures.huobi.li  and log in to your sub-account. If it is prompted that you have not currently activated USDT-margined swaps, you could activate through the following two methods: Note: you’re recommended to activate USDT-margined swaps for your main account first.   Method A: 1. Click “My” icon on the upper navigation bar and select “Sub-account” to enter into the sub-account management page. Select the corresponding sub-account, click “Set - Trading permissions”, and click the button to enable “Trading access for USDT-margined Swaps”.   2. Then you’ll see the prompt “Successful”. Log in to the sub-account again and you can begin USDT-margined swaps trading.   Method B: 1. Visit https://futures.huobi.be and log in to your main account. Click “USDT-margined Swaps” and follow the prompts to activate the trading permissions of USDT-margined swaps for your main account. 2. Click “My” icon on the upper navigation bar and select “Sub-account”. Enter into the sub-account management page and click “USDT-margined Swaps”. - If you already have sub-accounts, select the corresponding sub-account and click the button to enable the access.   - If you do not have a sub-account, click “Create Sub-account” and enter the information as required. 3. After your sub-account is created, you could refer to the guide from step 1 to activate the trading permissions for USDT-margined swaps.