If you used desktop download software to prepare the 2021 return, it was only stored on your own hard drive or any back up device you used. It is not stored on in an online account. Check your hard drive to see if you really deleted it--it might still be there. Check your trash can--you might still be able to rescue it if you did not empty the trash.
desktop versions create a backup. it's a hidden file in the Turbotax folder (under users/documents in a windows computer) that starts with a "~". even when you delete the actual tax file the backup should still be there unless you deleted that also. just remove the tilde and the double click on it to open. you can then save it. then the 2021 file should be there when you start 2022. if you deleted both then the only place either file might be the trash folder.