We will need a bit more information to help you. 

What state and school district are you referring to?

In 2020 I paid (by check) Ohio estimated school district tax for the 2020 tax year. I cannot find where to enter that when completing my 2020 taxes.

With TurboTax Online open, 

1. Click the Pick up where you left off button, if it’s present
2. Let the whole page load
3. Click Federal in the left pane
4. Click the Deductions & Credits link at the top
5. Scroll down to Estimates and Other Taxes Paid; click the Show more dropdown to the right
6. Click Start to the right of Estimated Tax Payments
7. Click Start to the right of Local estimated taxes for 2020
8. Answer Yes to Did you pay local estimated taxes for 2020?
9. On the How much did you pay in local estimated taxes? page, you’ll be able to make your entries.

If a taxpayer was a full-year or part-year resident of Ohio, and a resident of a school district that levies an income tax during all or part of the tax year, she needs to file Form SD 100, School District Income Tax Return.