From your ZenMaid dashboard, go to Scheduling > Calendar View.

Select and click the recurring service you wish to edit the default notes for.

Once the appointment details window opens on the right side of the screen, scroll down until you see the Notes section.

If you wish to keep the note on all the appointments of the recurring service going forward, tick on the Keep this note on all appointments of this recurring service box.

To make the note visible only to office manager tick the Make this note private (visible by your office manager only) box.