Any 2021 vouchers are only recommendations. It seems you owed tax this year, so Turbotax is recommending you pay additional estimated payments for 2021. You don't have to use them if think your tax situation will not require them. You can pay a different amount, if you determine that a different amount is correct, and if you make a payment online at www.irs.gov/payments, you don't even need the paper voucher form.
Turbotax will not make estimated tax payments for you, and the IRS will not automatically debit your account for estimated payments unless you specifically enroll in that service on the IRS web site.
This has nothing to do with your 2020 tax due. That is due in full April 15, and you can pay by direct debit on your tax return, or select "pay by mail" and make your own payment arrangements (check or electronically or credit card).
