I’m trying to fill out a fasa form they’re asking for the 2021 form address I looked it up and put the exact address that’s on there and they’re saying unfounded .

Where are you seeing that the FAFSA application is asking for any type of 2021 form address?

The current 2023-2024 FAFSA Application only asks for your current mailing address - https://studentaid.gov/sites/default/files/2023-24-fafsa.pdf