If you are reading this you probably have one of the newer chaimberlain garage door openers and have run into the same problem everyone else has, you cant just hit the 2 wires together and have the switch open the door. it has a serial chip built into the button.
Some have soldered a spare remote ($40 ) then you still have to hope the battery doesn’t die in it + zwave momentary switch. ( I use FS20Z-1 ).
The wall button is
$11 from amazon and the momentary relay is $40.
its databus not just 2wire signal like old openers.
Think of it more like the opener is sending a “whats my password” signal to the button and the chip on the button sends the password back.
You still need the white/red wired connected to the button, I soldered some wires ( blue/purple ) to the rear of the button to connect to the white/red on the chaimberlain.
The switch you have to be careful when soldering, It has a lot of components on the board. I used wires with prongs on the end so I put a decent ball of solder on the end then some flux on the button prongs. I used a multimeter to figure out which prongs on the switch would mimic the button being pushed in. one pin left side one right side ( with button vertical ).
I hooked the 2 wires ( gray and white ) to the 2 leads coming out of the FS20Z-1 go control relay.
I had to go into IDE.samsung and click devices then the go control relay and change the type to "virtual momentary zwave relay "
this turns the relay to be just a 1 second momentary relay so it mimics hitting the button.
I also use LGK Virtual garage door opener
and a TILT-ZWAVE2-ECO ( 24$ garage door tilt sensor )
Here are some pictures
I might rewire it to be a little cleaner since I just kind of threw the button in a project box I had and threw it up in about 5 minutes after soldering.