I haven't used that specific item but I would expect it to work similarly to the pressure plate items I used. In the scripts property of the plate, make sure PUZZLE_PressurePlate is attached. Then look at the properties. You will see EventOff and EventOn input variables. You can enter text strings there and whenever they are activated you will get an associated CharacterItemEvent
event to fire.
For instance, my pressure plates had 'activate' for EventOn and 'deactivate' for EventOff. I would catch the plates triggering with:
CharacterItemEvent(_, ITEMGUID_PUZ_PressurePlate_Floor_Left_891a0d4f-4ced-446d-ad8c-fa34b6b4c086, "activate")
CharacterItemEvent(_, ITEMGUID_PUZ_PressurePlate_Floor_Left_891a0d4f-4ced-446d-ad8c-fa34b6b4c086, "deactivate")
The first argument is the character GUID, which I did not need, but you could grab that value and use it to teleport the character that activated the plate.