Zooz Zen21 in group association

I recently set an association between a Zen21 On/Off switch and a GE On/Off Plug-In Smart Switch. The Zen21 (trigger device) is used as a wall switch that controls a lamp pluged into the GE outlet.
Zooz provided directions as follows:

To set direct association, click on the trigger device in the Vera dashboard, then go to Device Options and under Associations enter 2 for Group ID, then Add Group.

Then click on Set and select the device you’d like to trigger.

If you’re dealing with battery devices in this set-up, you need to wake them up for the settings to go through.

These instructions are slightly different than what is found on MiOS Wiki. (though that page is from 2016)

FYI, for the Zen30
To associate the relay as a trigger for another zwave device, the group information has to be programmed on the dimmer device and not the relay device (the trigger device).
From Zooz documentation: The relay supports Group 3 with up to 5 devices and will send BASIC_SET report to other devices in Group 3 if its status changes
Vera Plus creates two devices at inclusion: one for dimmer and one for relay. They are separate and both have ‘device options’ submenus as well as other submenus. But only the dimmer accepts the group information.