how do i set up retirement plan in online payroll? Employer match will be Traditional IRA (Pre-taxed) employee deferrals will be Roth IRA (after-tax)?

You can set up a retirement plan in QuickBooks Online (QBO) under the Deductions & Contributions section on the Employee page, Ochmra.
 

Here's how you can do it:

1. Log into your QBO account.
2. Go to Payroll, then Employees.
3. Choose your employee.
4. In the Deductions & Contributions section, select Start or Edit.
5. Click + Add deduction/contributions to create a new retirement plan.
6. When finished, select Save.

However, the Traditional IRA (pre-tax contributions) and Roth IRA (after-tax contributions) are not available in QBO. We recognize the value these retirement plan options hold for your business. Because of that, we encourage you to share your Feedback with us. To do so, follow the steps below:

1. Click the Gear icon in your QBO account, then select Feedback.
2. Describe your ideas or suggestions for improvement.
3. Click Next to submit the Feedback.

Your input helps us improve and meet your needs effectively. To stay informed about updates and new features, we recommend following the QuickBooks Online Blog.

Also, you might want to explore this link for deeper insights into your business finances through payroll reports, such as the Payroll Summary by Employee. 
 
The Community is always ready to deliver further assistance in setting up your employee payroll deductions & contributions in QBO. This thread is open for additional queries you have.