The vouchers that you're mentioning are simply a "suggestion" from TurboTax that the program generates if a taxpayer owes extra taxes at the end of the year. If you are certain that you don't need to file estimated taxes for 2019, you can ignore the vouchers.
See the TurboTax FAQ info below.
https://ttlc.intuit.com/replies/3301872
*** 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.***