Seems your MacBook Air or other Mac would need Big Sur macOS11.x
See 'how to get old versions of macOS' from Apple here.
https://support.apple.com/en-us/HT211683
"Safari uses these links to find the old installers in the App Store.
After you download the installer from the App Store,
the installer opens automatically."
- macOS Big Sur can upgrade Catalina, Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
• Big Sur is compatible with these computers - Apple Support
https://support.apple.com/en-us/HT211238
Your Mac may/not be capable of running Monterey.
The MB/Air has limited hardware upgradeability.
Learn how to upgrade to macOS Monterey, the latest version of macOS.
You may be able to upgrade OK but before you go try, make backups
of your system on external USB 2TB HDD for Time Machine. Unlikely if
you could actually 'revert' to older; instead you'd need to reinstall one.
Good luck & happy trails! ☺︎