On 2017 1040, where can I enter tax payments for FY 2017 (made AFTER extension filed)? They are neither estimated paid during 2017 nor with payment with an extension.

To enter  taxes paid (Federal, State, Local)

•    Click on Federal Taxes (Personal using Home and Business)
•    Click on Deductions and Credits
•    Click on I'll choose what I work on (if shown)
•    Scroll down to Other Taxes Paid
•    On Other Income Taxes paid in 2018 click on the start or update button

Yes, thanks, I saw this section. Taxes paid AFTER the due date/extension don't seem to fall into any of the categories offered by the software in this section. (I filed an extension, no taxes were due but I made a payment (after the filing deadline) just in case.)

the 3rd one from the bottom of my screen shows balance due on 2017 paid in 2018.

I'm working on a 2017 return... and the TT software has an entry for balance due in 2016 paid in 2017. In a 2017 return/TT software, I want to make an entry paid for 2017 tax liability paid AFTER the filing deadline. Maybe I have to file it in the return for the year I paid?

Yes, it does get entered in year it was paid as federal taxes paid is a State tax deduction for some states. When I answered above I thought you were doing the 2018 return.