if your 2020 return was not on extension you forfeited any refund by not filing timely. If on extension. you have until 10/15/2024. if you owe there is no time limit for the IRS to collect. any year prior to 2023 and after 2019 can only be prepared using a Turbotax Desktop App. they can't be e-filed. each year is a separate purchase, full pc or mac
https://turbotax.intuit.com/personal-taxes/past-years-products
you may want to check the IRS website. perhaps free file is available for the open years.
https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free
