How back-up my Mac to iCloud?

Gym_Love wrote: Please assist me with Backing up my Mac to iCloud

Just to be clear, iCloud is primarily a synchronization service, not a full backup service. When you move files & folders to iCloud Drive, they are then available on your iPhone and iPad and to a browser at iCloud.com. And when you make changes to a file on your iPad, those changes are copied to your Mac. This is super cool! It's a backup, because if your Mac gets run over by a truck, all your files are safe on iCloud drive.

But it also means that if you mistakenly delete the middle third of your Master's Thesis, then it is also deleted in iCloud and on all of your devices! In that case, it's not really a backup. iCloud synchronizes mistakes as well as positive changes.

So--don't depend on iCloud as a real backup. We use iCloud for a quick, easy way to backup and synchronize our daily work, but we keep a real backup, as well. I use Time Machine to make a real backup on an external drive. TM does incremental backups-- it backs up the changes you've made. And if you accidentally erase an important file, you can go back to the way your computer looked last week, and recover that file! This has been a lifesaver!

Just to be clear....

See How to back up your Mac - Apple Support