Yes, you must have an existing mechanical chime.
Wyze Video Doorbell v2 uses its Wyze Doorbell Chime Controller to work with your existing chime. Even if your old chime is broken or not working, you can still use this doorbell and connect the chime controller!
However, if you don't have a mechanical chime at all in your home, we suggest Wyze Video Doorbell Pro. It can be used wirelessly and relies on its included Bluetooth-enabled chime.