I didn't know about the CLIOne thing I don't understand is, why there is no webUI integration to back up some folders. As you already can use the proxmox-backup-client in CLI to do host backups and backup any file, folder or block device to your PBS server. I for example already use that to backup my PVE config files as well as the whole system disk on block level. It's just not simple to set that all up so most people won't use it.