How do I find 2021 AGI?

https://ttlc.intuit.com/turbotax-support/en-us/help-article/internal-revenue-service/find-last-year-agi/L0SiDtTNI_US_en_US?uid=lg4grrj6

Find a copy of your 2021 tax return.  The AGI will be on Line 11.

You need your 2021 AGI to efile 2022. The AGI is on 2021 1040 line 11. If you filed a Joint return you use the same AGI for each spouse.

How to find the AGI.
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/01/25947

If you didn't file 2021 or filed it later in the year or mailed it, then try entering 0 for the AGI. If that doesn't work you will have to print and mail your return.

Or request a transcript from the IRS
https://www.irs.gov/individuals/get-transcript