Then use this https://cotaxaide.org/tools/Refund%20Calculator.html
to calculate the taxable amount of the refund.
The basic idea is to find out how much you benefited from the itemized state income tax. Eg if your state income tax itemized was 1600 but your state sales tax would have been 1500, TT would have selected state income tax because it gave you a higher deduction. However if the benefit over sales tax was only 100, then your benefit was only 100 and only 100 was taxable.