I had one renter complain that they couldn't get the wifi network and password (and again ask for a refund), so I just gave in and put it in the listing. Airbnb has a way to enter it securely, but most guests never figure it out. Airbnb should probably text the wifi network and password automatically when a property is booked
Update: I'm on phone with AirBNB support about this right now. Frankly their phone support is pretty poor, eventhough I'm a "super host." They can't seem to answer basic questions about how the wifi network and password is provided to guests