Hi ihtemamrentacart,

Thanks for the screenshot.

You can click the drop-down arrow beside the Add check option so you can add an expense transaction in your bank register. Let me guide you through. 

1. Click Accounting on the left menu.
2. Go to the Chart of Accounts tab. 
3. Select the account.
4. Click the drop-down arrow beside Add check.
   
5. Select Expense.
6. Fill in the necessary information.
7. Click Save. 

You can create another account in QuickBooks Online (QBO), here's an article for more information and detailed steps: Create Subaccounts In Your Chart Of Accounts in QuickBooks Online.

Don't hesitate to keep in touch if you need anything else. I'm always right here to help.