Where do you report state withholding tax ?

If you had wages, the state withholding should be reported on your W-2.  Once you enter the W-2 information no further entries are needed.

If you made estimated state tax payments yourself, you can report the estimated tax payments using these steps:

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, click on the Start/Revisit box next to the type of tax payment (Federal, State, Local).  
4. Enter your payment(s) on the next screen, How much did you pay in federal [or state or local] estimated taxes? Select the locality from the drop-down list and enter the amount paid in the box. 

[Edited | 4/8/2020 |  11:27am PDT]