M365 OneDrive (How To) Set Up OneDrive Sync
The OneDrive sync user is available for those who prefer managing their files using a desktop application over a web browser. To use the desktop sync user, you must install it and sync your library. Once synced, your OneDrive for Business library will appear as a folder on your computer from which you can view, upload, and share.
Sync files with OneDrive in Windows: This links to Microsoft's instructions on how to set up the OneDrive sync user on a Windows computer.