If you live in an apartment then the chances are all the building telephony services enter in a utility room or similar and are distributed from there to the individual apartments, obviously OR don't know or have any record where this is as the building developer installed it, so in these circumstances it's reasonable for them to ask that you provide access to this room and ensure they can get at the DP ( distribution point ), after all it may be a room that's normally locked, if access isn't available they probably would wait a short while for you to obtain access for them, but would ultimately walk away and book the job as no access , does your building have a caretaker or someone responsible for the communal areas ?, you may have to arrange with them to let the OR engineer into the utility area