If you mean the state sales tax, that would be reported INSTEAD OF state income tax, which usually is not advantageous unless you did not earn much in earned income (W-2) and therefore paid little in state income tax.
You would enter that on the Federal return under:
Deductions & Credits
Estimates and Other Taxes Paid
Sales Tax START or UPDATE
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"