You made an estimated payment OR a payment with an extension to file? They are different and go on different lines on your tax return.
Did you use Turbo Tax to file the extension? Then it should automatically show up on 1040 Schedule
3 line 9. And go to 1040 line 31. See if it's there.
Estimated payments are on 1040 line 26.
If it didn't show up on your tax return the IRS should catch it and add it in for you. Either increasing your refund or decreasing a tax due. They may even send it back to you.
