Turbotax is not designed to track your business spending and prepare quarterly estimates. Turbotax only prepares a tax return at the end of the year, and Turbotax Online currently only prepares 2019 returns.
To track your business income and expenses, you want an accounting program like Quickbooks. There is a Quickbooks Self-Employed Online bundle that is a monthly subscription and includes Turbotax at the end of the year. Or, you can buy higher levels of Qucikbooks depending on your needs.
https://quickbooks.intuit.com/pricing/
If you know the amount of the payment you need to make, just make an online payment at www.irs.gov/payments, you don't need a voucher for online payments.
