No. Once you've made payment for your 2018 TurboTax program, you won't need to pay again to file.
You should know, however, that the accepted extension gives you extra time to FILE, but not to pay any taxes due. In order to avoid penalties and interest, you should make payment before the filing deadline of April 15, 2019.
*** 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.***
