Did you know? Once a friend shared a OneDrive folder with you, you can add it into your own OneDrive list of folders and optionally synchronize it as usual with OneDrive desktop app from Windows 10, for example!
To add a shared folder into your collection, simply go to OneDrive.com, click Shared from left side, select the folder you want, and click Add to my OneDrive space from the top menu. You can give the folder a different name, if you wish, to easily recognize it. Finally, you’ll then be able to find the newly added folder also in OneDrive app’s settings so you can select it for local drive syncing!