How did you file before? By mail? When did you mail your 2021 return?
ENTER 0 FOR AGI. The IRS took a long time last year to process 2021 returns so the AGI didn't get entered in time. Especially if you mailed it. That works for most people. See,
https://ttlc.intuit.com/community/rejections/help/what-if-i-entered-the-correct-agi-and-i-m-still-ge...
Be sure to attach copies of your W2s and any 1099s that have withholding on them. You have to mail federal and state in separate envelopes because they go to different places. Get a tracking number from the post office when you mail them for proof of filing.
To try fixing or entering it go back though the File tab again.
