Box 2 should not be interest. Interest would come on a 1099 Int. Box 2 should be the refund from the year in box 3 that you received in 2021. It may be taxable on your 2021 federal return. If you took the Standard Deduction on your 2019 return it is not taxable and you don't need to enter it.
A State Tax Refund is taxable if you itemized deductions on that prior year's federal return and took a deduction for state income taxes instead of the sale tax. You got a deduction benefit for it so now you have to include it as income. If you took the standard deduction it is not taxable and you don't need to report it.
If it really is interest then you need to enter it as interest and pay tax on it. Enter it like a 1099-INT and put the amount in box 1.
