IRS rejected 2020 electronic filing. I don't want to mail in as they are behind in entering the data.
Try entering a 0 (zero) for the 2019 AGI and e-file again.
I did that and it was still rejected.
@digger41 wrote: I did that and it was still rejected.
Then your only option is to print and mail the tax return.
See this TurboTax support FAQ for printing a tax return form mailing - https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online/01/26258