If you want to trade crypto contract, then you need to transfer cryptos from your crypto account(the far left one) to crypto contract account(the middle one).
If you want to trade traditional securities like stocks or commodities, etc., then you need to transfer cryptos from your crypto account(the far left one) to crypto collateral account(the far right one).
Below pics demonstrate how to transfer cryptos step by step.
Step 1: Select and click the crypto you want to transfer
Step 2: Select the sub-account you want to transfer funds in
Step 3: Enter the amount
Step 4: Click “Transfer” button
Note: you need to complete Google 2FA verification when you transfer crypto to crypto collateral account