Does anyone know why payroll features would be missing from Quickbooks Online set up? I'm using a free trial of the Core version?

I can show you how to add these deductions to your employee's profile, @riverside3.

You’ll just have to go to the Payroll tab and then Employees menu.

Here’s how:

1. From the Payroll menu, go to the Employees tab. 
2. Click the employee’s profile and on the page that appears, scroll down to 4 Does [employee name] have any deductions?.
3. Click the + Add deductions link.  
4. From here, follow the on-screen instructions. 
5. Select OK and then Done.

Here’s more information on how to set up voluntary deductions in Online Payroll.

Let me know if there's anything that I can help. I'm always here to assist. Have a good day!