I want to file a 1040X for 2020 electronically ( original return was not done in proseries ) I know 1040X wont be available to e-file till 03/18/2021

I am following this instructions but it said is for 2019

1. Open a New Return.
2. Enter the taxpayer information on the Federal Information Worksheet.
3. Press F6 for the open forms menu.
4. Type X and press enter to open.
5. Check the box current box for This return is for Calendar year.
6. Manually enter the original amounts in Column A.
7. Manually enter the corrected amounts in Column C.
8. Column B will be calculated automatically once amounts are entered in Columns A and C.

but is not working it keeps giving me an error 

cannot electronically file for 1040X when the original return was not successfully efiled.