There's a specific part of the worker's setup where you need to select if the employee is a head of household, mjuby.

I'd be glad to share these steps with you:

1. Go to the Payroll menu and proceed to the Employees tab. 
2. Click Add an employee.
3. Enter all required information and click Enter W-4 form in the What are this employee's withholdings? section. 
4. Select 2020 or later.
5. Proceed to the Federal filing status and select Head of Household.
6. Scroll-down to the state taxes section and select Head of Household in the drop-down list for Filing status.
7. Click Done. 

Let me also share these articles with you for more details about managing employees in QBO:

• Employee Withholding Allowances
• Add A New Employee To Your Payroll

You can always reply or visit us again anytime you need help while doing tasks in QBO.