I looks you have two issues: the
IR
sensor (or the code handling it) not working and the missing notification.
You could first mock the
IR
sensor (a simple way would be changing from
if (digitalRead(in))
to
if (1)
in order to test the notification part of the code. Then you could face the people detection problem. There are many resources available on the web on this very topic, see, for instance
Overview | PIR Motion Sensor | Adafruit Learning System[
^].