Setting a sensor as a binary sensor

My “config parameter” area is greyed out so I can’t select anything.

It did recognize as a binary sensor when I installed it (in my case it’s a door/window entry sensor, which Home Assistant correctly named as binary_sensor.XXX) but I have the same issue with it perpetually being stuck to ‘on’ even though the sensor light beeps to indicate that it is recognizing open/close.

Any thoughts on why I might not be able to set a config parameter?