Question about wireless garage door opener and Sonoff 4CHPRO

I’m rigging up a Sonoff 4CHPRO to serve as a garage door opener and integrate with HA. I flashed ESPHome on the unit and I’m ready to go. I have three garage doors. Two of the openers are hardwired. I got them to function with the Sonoff relay no problem. I found out that the remote for the third door is not hardwired. Instead it sends a wireless signal to the motor unit.

My question is whether anyone knows of a way to rig the PCB for the remote so I can feed a dry contact signal from the relay to it. The remote is Overhead Door 39903R. Also goes by the part name OWWCP. The PCB inside the remote is model 39773A Rev05. You can see it in the attached photo. The button to open the door is labeled ‘S1’ and is found just above the ‘AAA’ marking where the batteries go. There are four solder points on this switch and five points on the top of the PCB where I could also solder wires if this would get me to a solution.

This is a headscratcher. I don’t know how to interpret a PCB just by looking at the traces.

The 2 switches/buttons at top of PCB simply open and close

Open = do nothing
Close = make door move

Just figure out which of those 4 shiny solder points the corners equal a pair that when shorted together closes the circuit.

Look at the back side and it may be more obvious.
OR
Just short pairs together while powered until it words
OR use meter and check while powered or unpowered

Another thing you can try is close the relay
Directly on the mounted garage opener.

EDIT

I only saw S2 and S3 at top but you need to check S1 also. Really you will know which of three to use based on the button you push when assmebled

Thanks for the input.

S1 opens and closes the door.
S2 locks the door so it won’t move.
S3 toggles the light on the motor housing.

I’ve got enough info from your post to make a first attempt at reverse engineering the remote.

Later edit: It worked brilliantly! Thanks for the assistance.