As a non-resident, I cannot find where Turbo asks me to input the Pa state tax withheld. Where do I go?

If the Pennsylvania (PA) state tax withholding is not on a W-2, and you have PA state withholding that you are unable to enter in one of your income documents, then you can enter it using the steps below.

1. Click on Federal >  Deductions & Credits. 
2. In the Estimates and Other Taxes Paid section, click on the Start/Update box next to Estimated Tax Payments.
3. On the next screen, Income Taxes Paid, scroll to Other Income Taxes Paid in 2021, click on Withholding not already entered on a W-2 or 1099, Start/Revisit 
4. Next to the type of tax payment (Federal, State, Local). Enter your payment(s) on the next screen, How much did you pay in federal, or state or local 
5. Select the state and enter the amount

There is generally no isolated entry place, in TT, for "withholding".  The withholding entry is associated with the income. So, it depends on the source of the income and what kind of IRS document (W-2, 1099 etc) was used to make the entry.  

That said, see  @DianeW777 reply for the "last resort" place to enter withholding.  The most common use for this place is state income tax withheld at a real estate sale closing. 

This worked well. Thank you!

Dave

Thank you for the additional explanation. I appreciate it.

Dave