Let me address these in order with a few trouble shooting questions of my own:
1) The back door sensor appears broken. Will not trigger a close and open. I tried opening and changing battery but nothing. It worked out of the blue twice but that is it. Having to bypass to set alarm.
How far is the magnet from the sensor when the door in closed? What is the door made of? Might there be any metal interfering with signaling? What all is between the sensor in this location and the panel?
2) the panic button is not working. Any idea why that would be? I push it and nothing happens — no light on the panic button or alarm.
How long are you holding the button? Panic buttons require 2-3 seconds of holding the button down to set off the alarm/turn the indicator light red.
3) if I want to add more sensors can you all do that through alarm.com or would I need to program?
Once you have the system, you would need to program any additional sensors you’d like to add. However, we are happy to assist you with any questions you may have. Many of the sensors we offer have videos showing programming on their product pages, have instructions included from the manufacturer (sometimes also linked to on their product page) and also might have instructions listed here on the forum. Were there any sensors in particular you had questions about?