If you want to take a single manual Virtual Machine backup then you simply go to "ManageVPS" and take an incremental backup.
You can also take multiple Virtual Machine backup. Simply go on list backup plan and edit your backup plan. You can take incremental backup, all the machine present in that plan will have their backup taken.
If enduser has backup enabled in the backup plan then endusers can also perform backup via the enduser panel.
Admin user can restore backuply incremental backup from restore vps wizard.
If enduser restore is allowed in the assigned backup plan then enduser will be able to restore Virtual Machines from the enduser panel.