I'm suggesting this because it's pretty trivial to add. The Amazon s3 protocol is used by many cloud backup solutions. There is a linux command s3cmd you can use to upload files to an s3 bucket. There is already a yum package for this: yum -y install s3cmd.
What makes it so trivial to add to cyberpanel though? Well, you don't even have to add any configuration for it yet if you don't want to. To configure your s3 authentication, you run the command:
After that, you can backup to a bucket like this:
s3cmd sync /home/example.com s3://my-bucket-name
All you would have to add to cyberpanel option is an input for the bucket name and a tooltip telling them to first run the configure command if they want to use it.
Thanks for the great panel!