If you were not being claimed as a dependent in 2020, you should be able to claim the Recovery Rebate Credit on the 2020 tax return. You have until May 17, 2024 to file the 2020 return for the credit.
To complete and file a 2020 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2020 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2020 tax return can only be printed and mailed, it cannot be e-filed using TurboTax.
