Depends ... usually the state income tax withheld is reported on some sort of tax reporting document like a W-2, 1099-R, etc.   and is entered on the  input screen for that form.   Did you not see the state section for that income on the screen ?   

"For itemized deduction"

Do you mean you are trying to enter itemized deductions on a Schedule A?   Are you asking where to enter the state and local taxes you paid in 2021--such as property tax, sales tax, etc.?    State and/or local tax you PAID is not quite the same thing as state tax withheld.   

State tax withheld would be shown in box 17 of a W-2, for example---and you would enter that when you enter the data from a W-2.  If you have some other sort of tax document that shows tax withheld, tell us what the document is.   The documents vary, so we need to know what you are trying to enter.

Please clarify what you are trying to do and what you are trying to enter.