After you file

I filed my taxes early and my CA. Refund was deposited and my federal fee was withdrawn. I need to amend my taxes using the lookback rule using my 2019 income to claim my EITC. The IRS site says efile amendments are now available and to check with your tax preparer. I used TurboTax app and read on turbo tax that it would be updated to support this feature on 3/25/2021 and I could sign up for a email notice when its available. It's still not available. I don't have a printer to print 1040x and mail it in.