I did not use turbotax to file my 2021 income tax return. Can I redo my 2021 income tax using turbotax and refile?

Torbotax will not allow you to do a re-file since you haven't filed through it last year but you could use CRA My Account for that: https://www.canada.ca/en/revenue-agency/services/e-services/e-services-individuals/account-individuals.html