This looks like a very guest-hostile intercom, I would just stare at it and read instructions, then read them again, then think why is it A and Z and not up and

This looks like a very guest-hostile intercom, I would just stare at it and read instructions, then read them again, then think why is it A and Z and not up and down... And also why I cannot just enter the number. At some point I would give up and just take out my phone and call the friend "hey, can you buzz me in? I'm in front of the door".