you need to upload the *tax2020 file the desktop may be best because then you'll know where it is
then you start TurboTax for 2021. you must select start a new return
a blank list will likely show up
then you need to browse to your desktop and select that file and click on open
that's it the data should transfer.
you can then move the 2020 file to wherever you want on your computer
note that the transfer must be done before you start 2021. if you have already started that year transfer is not possible. that leaves you with the option of either manually entering an need 2020 tax info or deleting 2021 and starting over
