Download pvebackup 1.0.0

Easiest: install it from Package Center, which picks the right version for your NAS and offers every update. How

Plus and rack models with an Intel or AMD CPU, e.g. DS224+, DS423+, DS723+, DS923+, DS1522+, RS822+.

Models with a Realtek or Marvell ARM CPU, e.g. DS124, DS223, DS223j, DS220j, DS120j, DS118, DS218, DS418. Backups are slower on these.

Not sure which one? DSM shows the CPU under Control Panel → Info Center → General, or see Synology's list.