I'm sharing a TurboTax FAQ below that will instruct you on entering your payment made with extension. Please post back if you have further difficulty.
https://ttlc.intuit.com/replies/5294887
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***
