Stupid Newbie Q - Setting up scene-capable devices

I’ve trying out Vera (UI7 and the new VeraEdge controller) with the Leviton DZMX1 scene-capable in-wall dimmer switch and the DZPD3 scene-capable plug-in lamp dimming module. All I want is the MX1 to turn on/off it’s load and act as the master switch for the PD3-connected floor lamps.

Can’t figure out how to do it.

I’ve gone into the MX1 Device Options, Set the Group ID to 1, clicked the ‘Set’ button and checked the PD3 device. The text box next to it enables, but I’m not sure if any specific value goes there or not.

Then I go into the PD3 Device options and repeat the process, selecting the MX1 device there. Same Group ID = 1.

Have never done any z-wave associations like this before, so I’m probably missing something simple. Coming from a Wink which was woefully inadequate and unreliable.

Would really appreciate any advice.