To trade futures contracts in Bexplus, you need to deposit BTC in your account firstly. If you haven't bought BTC before, you can purchase some from references fiat-to-crypto exchanges. When you finished purchasing, you can directly deposit BTC in your Bexplus account. 

1/3

Open Bexplus.com, choose “User Center” and click “Buy BTC”

2/3

Some recommended bitcoin exchanges where you can buy BTC via fiat currencies, credit card, paypal, etc are listed on the page. Read through and choose the one you like, then, click "Buy" button to visit the exchange and complete BTC purchasing. 

3/3

After purchasing, you can click account name > deposit, and paste the BTC address to the exchange wallet where you bought BTC from. When BTC credited in your account, you can check in balance column and start trading BTC, ETH or LTC futures with 100x leverage. 

Note: Here is the guide on how to deposit BTC in Bexplus.