A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
Hi T.Sanj,
Thanks for posting the question on our forum.
Notebooks can’t be saved on our Mac, it need to be stored on OneDrive.
When you edit the notebooks, it will automatically sync the content to OneDrive.
You needn’t to backup it manually.
About the Time Machine feature, as the notebook isn’t stored on Mac, Time Machine only backup
the OneNote cache, it is in fact a copy of all opened notebooks but in a special binary and fragmented format for sync purposes only. It's not usable as a backup because you can't restore any information from it.
Given the situation, I suggest you still check it via OneDrive, you can check if is there any other OneDrive account where you store the notebook.
If this is not your situation, you are welcome to post back and provide the detailed information, such as where did you store the notebook, personal OneDrive or OneDrive for Business?
Regards,
Qing