On the back of the call button, there's a pair of set tiny rocker switches. Flip the top one & you're ready to program the code.
On the front - say the code is 341 - you'll hold the reset button down until it begins to flash. Next you'll hit the button 3 times, hit the reset, hit the button 4 times, hit reset again, then hit the button once followed by reset. It will then flash the entire code sequence. Turn it over & flip the switch back to the original position. Test it by hitting the button & listening for the dept.
I have a list of codes somewhere.....lemme get back to you.