You will have to file a 2020 and 2021 tax return for the Recovery Rebate Credit. The tax year 2020 return must be filed on or before May 17, 2024 for the credit. If filed after that date the credit/refund is forfeited.
To complete and file a 2020 and 2021 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the desktop editions for each tax year required from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2020 and 2021 tax return can only be printed and mailed, they cannot be e-filed using TurboTax.
Use a separate envelope for each tax year when mailing the tax returns.