If you try to download the latest OneDrive from the Mac App Store today, you will find it requires . New installations on older systems like 10.13.6 are now blocked. The Hidden Workarounds
If you must use OneDrive on High Sierra, you cannot download it from the Mac App Store, as it will only offer the latest version. Instead, you must use a : onedrive for macos 10.13.6
If prompted, choose to compatible with your OS. If you try to download the latest OneDrive