OneNote for Mac keeps all of your notes in the cloud, by syncing them to OneDrive automatically. This lets you open and edit your notes anywhere on all of your devices. Sometimes, however, the sync may be interrupted or may not happen at all because you’re offline. When you’re back online, you may want to sync your notes manually.
Sync your notebook manually
To open the list of notebooks, click Notebook.
In the notebook you want to sync, click the arrow and then click Sync.
More related info
In the list of notebooks, a small sync icon shows the sync status. If you see a yellow triangle with an exclamation mark, synchronization errors may have occurred, or you are currently offline.
If you get a sync error, you may need to log in again. This may occur, for example, if you’ve changed your account password since your last login. For more information see how to login to OneNote.