If you were claimed as a dependent on a 2020 and 2021 tax return you were not eligible for the stimulus payment.
If you were eligible and did not receive the EIP payments in 2020 and 2021 then you will have to file an amended return, if you have already filed those tax returns.
However, you should check your IRS Tax Account to see if the IRS has already sent those payments but you never received them.
Go to this IRS website for the Tax Account - https://www.irs.gov/payments/your-online-account
See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...
If you never filed a 2020 and 2021 tax return -
To complete and file a 2020 and/or a 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 multiple tax years.
