If you downloaded 2020 to mail BUT you have not mailed it yet you can switch to efile. Click on Add a State to let you back into your retun.
https://ttlc.intuit.com/community/e-file/help/how-do-i-change-from-mail-to-e-file-in-turbotax-online...
FYI - Even though you have 2019 AGI its common this year for it to reject. If the AGI rejects try entering 0 for the AGI. That's because last year the IRS took a long time to process 2019 returns.
