How do I enter the payment I made with form 4868 - Application for Automatic Extension of Time

To enter, change or delete a payment made with an extension request (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 Estimates and Other Taxes Paid
• On Other Income Taxes, click on the start or update button

On the next screen select the type of extension payment made and click on the start or update button

The federal extension payment will be shown on Form 1040 Line 70

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

But be sure it is not already there before you enter it.  If you used Turbo Tax to do the extension it may already be filled in.