Check the box next to to allow it to clean system-level files .
: You must use the version specifically for your OS. Visit the Titanium Software downloads page and select the macOS Monterey 12 version (OnyX 4.2.1 is the latest stable release for Monterey, though 4.1.9 is also common) . OnyX 4.1.9 for macOS Monterey 12
: Go to System Preferences > Security & Privacy > Privacy . Select Full Disk Access and click the lock to make changes. Check the box next to to allow it
: Open the downloaded .dmg file and drag the OnyX icon into your Applications folder . Grant Permissions : OnyX 4.1.9 for macOS Monterey 12