Amend 2020 California return online

Hi,

 

According to https://ttlc.intuit.com/community/e-file/help/can-i-efile-an-ame[product key removed]n/00/27183 (as of 9/19/21) it is possible to e-file an amended  CA return for 2020. How can I do this?

I was able to amend the federal returns electronically, but not  the state returns. Note this is for the installed version of Turbo Tax 2020, home and business,  for windows.

Thanks!