An amended 2020 return cannot be e-filed. The only way to file it is by mail. Print it, sign and date it in ink, and mail it in. Do not expect quick results from amending.
You can watch for information here:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**