What is the prior year AGI??

See this TurboTax FAQ on how to find your AGI

https://ttlc.intuit.com/replies/3301618


You can get free 2020 tax transcript from the IRS

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

If you filed late last year there is a good chance that the 2020 AGI never was entered into the e-file database. Try using 0 (zero) for the AGI.

If you filed an amended return use the AGI on the first filed tax return.

If it continues to reject then the AGI in the IRS database might be in error. Mail filing is the only option.

Also see: https://www.taxpolicycenter.org/taxvox/are-irs-security-tools-blocking-millions-people-filing-electronically

https://www.forbes.com/sites/howardgleckman/2021/04/26/are-irs-security-tools-blocking-millions-of-people-from-filing-electronically/?sh=529e1d891a76

Adjusted Gross Income (AGI) is on line 11 of Form 1040.  "Prior year AGI" is the AGI from last year's tax return.