Are you using TurboTax CD/Download or TurboTax Online?
Turbotax online
You can go back and open the returns in the version of TurboTax Online for the year you created them.
You can log into TurboTax Online 2022 here: https://ww1.2022.ca.turbotaxonline.intuit.com/
You can log into TurboTax Online 2021 here: https://ww1.2021.ca.turbotaxonline.intuit.com/
Previous years are not available anymore.