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 can type estimates paid in the search box at the top of your return and click Find and it will give you a link to Jump To it.
OR
To enter Federal or State Estimated Taxes Paid, including a state estimated payment made in Jan 2017 for 2016 (or Jan 2018 for 2017) go to
Federal on left
Deductions and Credits at top
Then scroll way down to Estimates and Other Taxes Paid
Estimated Taxes - click the Start or Update button
See this answer, it has screen shots
https://ttlc.intuit.com/questions/3896471-i-sent-in-three-3-forms-1040-es-for-a-total-of-966-in-2016...