backup to one drive

To find your actual pictures – to see where iPhotoPhotos has stored your image files – first open finder, and in the “Pictures” folder find the ‘file’ that is called ...

Photos Library.photoslibrary

Now, control-click (hold down the ‘control’ key while clicking) on the Photos Library.photoslibrary file:

There in Finder look in the Masters folder for Yearly & Monthly Pics.

The Apple Photos App stores photos in a compressed database file usually named Photos Library.photoslibrary inside the Pictures folder in your user profile.

You cannot transfer the database folder directly to OneDrive, as it requires a HFS+ or APFS formatted volume on your hard drive to operate.

You can export your photos from the Photos app into any folder you wish, including one on OneDrive by using the Export feature in the Photos' File Menu.

Its not recommended to access he Photos Library.photoslibrary file directly as you can mess up the database and corrupt it irrecoverably. It's better to simply use the Export Feature in the Photos app to extract any photos you want out of that.

You cannot. Time Machine cannot backup to any cloud service, not even iCloud. Time Machine backs up to external hard drives and networked hard drives.

Thanks Phil0124! :)