efiling an amended 2020 tax return

I am attempting to efile an amended 2020 tax return, providing my signature date as today's date 01/18/2022.  Turbotax 2020 premier is giving me the error message that the date must be in the year 2021. 

 

Is this a bug in Turbotax?  Can I file an amended 2020 tax return in 2022?