In order to e-file, I have to provide my 2020 AGI. The help tab says to find it on line 8b of my 1040 but there's no 8b line on mine, just 8 and it shows no amount.

[marianinousmc]

I filed jointly that year with my spouse at the time and I had no income to file.

[VolvoGirl]

You use the same AGI on the joint return to efile.

You need your 2020 AGI on the 1040 line 11 to efile 2021.

How to find last year's AGI

https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/00/25947

IRS how to find the AGI

https://www.irs.gov/individuals/electronic-filing-pin-request

Or You can request a transcript from the IRS

https://www.irs.gov/individuals/get-transcript