I found a check to pay estimated Indiana state taxes for 2021. Where can I enter that pre-payment on my Turbo tax state form?

You made a estimated payment?

To enter Federal or State Estimated Taxes Paid, including a state estimated payment made in January for the prior year, go to

Federal on left or at top (Personal for Home & Business)

Deductions and Credits at top

Then scroll way down to Estimates and Other Taxes Paid

Estimated Taxes - click the start button

Do not enter them as Other Federal Withholding!  Only enter them in one place.

For 2021 Federal Estimated payments should be on 1040 line 26.

You enter state estimated payments under the federal side (because they can be a federal itemized Deduction).  THEN after you finish filling out the estimates under Federal you need to click on the State Tab at the top and start the state return over for it to update.

You have to pick the right state from the drop down box and enter the right payment dates.