Microsoft aligns its OneDrive support with Apple’s "n-3" policy. This means they only support the three most recent versions of macOS. Because High Sierra is now several generations behind, the modern OneDrive app will not install or sign in on this version. ⚠️ The Compatibility Reality Ended in September 2021.
: If the desktop client fails to install or sync, you can always access, upload, and download your files through OneDrive Online via a web browser. Microsoft Learn Known Compatibility Issues Sync Blocks onedrive for macos 10.13.6