how to backup mac to icloud sync automatically

Then you have the option to move any files that were in your iCloud Desktop and Documents, back to your new local Desktop and Documents. If you choose to keep a local copy, your files in iCloud Drive are copied to a folder called iCloud Drive (Archive) in your home folder. Whether you decide to keep a local copy or not, a new Desktop and Documents folder is created in your home folder. If you turn off iCloud Drive or sign out of iCloud, you have the option to keep a local copy of your files that are in iCloud Drive.

From your Mac, go to Apple menu > System Preferences > iCloud.

You can move files from iCloud Drive to your Mac as you need them, or select all of your files and drag them to the place you want to keep them. When you turn off Desktop & Documents Folders, your files stay in iCloud Drive and a new Desktop and Documents folder is created on your Mac in the home folder. This is the critical part you need to be aware of when you turn off Desktop & Documents (and you DO want to turn that off):

How to backup mac to icloud sync automatically