Amend 2020 return in 2021

[Aussie]

Can I e-file an amended return for 2020 in 2021? If so how? I am in TT version for 2020 and when I try to transmit the amended return electronically it gives me errors saying dates have to be before 12/31/2020.  However I also see note in TT that says a change has been made to be able to electronically file prior year amended returns.  Am I missing something here or do I have to file by mail as only option?

[DoninGA]

Using the personal editions of TurboTax a 2020 federal amended tax return, Form 1040-X, cannot be e-filed it must be printed and mailed.

In the File section of the 2020 TurboTax program change your filing method to File by Mail

[Bsch4477]

You have to mail it.