Prior year returns cannot be efiled thru the TT system any longer ... you must print, ink sign and mail in the return.
If your return is ready to go then save a PDF of the return from the online system to mail. If not then follow the instructions here to complete the return : https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-finish-a-prior-year-return-that-i-...
When using the downloaded version to complete the 2020 return go to the FILE tab and choose to mail in the form return then the correct forms & mailing instructions will be presented in the PDF file.
