Get your taxes done using TurboTax

Try to do the years in order starting with the oldest one.  Then you can transfer into the next year.  If you use the online version  for 2021 you can transfer from the 2020 Desktop program.   Post back if you need to do that when you start 2021.  You can use Online for 2021 until Oct 15.  Then it shuts down to get ready for the next year.