Assuming the that you did not use the TurboTax online editions for tax year 2021 to file the 2021 tax return, you can clear your tax return.
If you have not paid for the online edition you are using, have not filed your tax return or registered the Free edition, then you can clear your return and start over with a lower priced edition. Click on Tax Tools on the left side of the program screen while working on the 2020 online tax return. Click on Clear & Start Over.
Note - Having a TurboTax online account does not affect in any way the status of a tax return you filed using another service or paid tax professional if you did use TurboTax to file the tax return.
Also, you could have used TurboTax for the 2020 tax return but it would have to be one of the desktop editions that you install on a personal computer. See this TurboTax website for prior year desktop editions - https://turbotax.intuit.com/personal-taxes/past-years-products/
