The CD/download is already available for 2020 returns although it will still require many updates. If you want to use online TurboTax you have to wait until December.
Desktop software:
https://turbotax.intuit.com/personal-taxes/cd-download/
You can also purchase the desktop software from various retailers such as Amazon, Costco, Best Buy, Walmart, Target, etc.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**