I have to file my taxes from the previous four years starting from 2020. How do I do so in the app?

It’s simple tax return But I do not see the option to start from a previous year. There must be a way to do it no?

Filing

No, you can't do past year's returns through the app. However we do have other products available for previous years: https://turbotax.intuit.ca/tax/software/prior-year-taxes