Mqqt status

I use some shelly switches in detached mode to control some zigbee smart bulbs in node red. Occasionally the bulbs will drop off line so I go into home assistant and toggle the relay so they reconnect.

What I would like to do in node red is when the flow runs to switch on/off the bulbs, i could check if they are responding and if not then toggle the relay.

When I deploy node red and look at the debug for this topic
zigbee2mqtt/Master Bath Ceiling Light 1/availability

It says “online”

but I cant figure out how to extract that info on a switch attempt and then of course how to use it after that.

any help much appreciated.

Craig