If you used the TurboTax Easy Extension to electronically file the extension request, Form 4868, and make the tax payment with the request, the payment should already entered on your tax return. Provided you used the same user ID for the 2016 online tax return as was used to use Easy Extension. You can check to see if the amount is on your tax return by clicking on My Account at the top of the program screen. Then click on Tools. Click on View Tax Summary. Then click on Preview my 1040.
The payment made with the extension request will be included on your tax return as a tax payment, Form 1040 Line 70, Form 1040A Line 46. It is not an estimated tax payment which would be paid using a Form 1040-ES.
To enter, change or delete a payment made with an extension request (Federal, State, Local) -
On the next screen select the type of extension payment made and click on the start or update button
Or enter federal extension payment in the Search box located in the upper right of the program screen. Click on Jump to federal extension payment