HAP, intended to help an accessory communicate with Apple's HomeKit, has two faces - commercial and non-commercial.
- In the case of commercial, z wave would have their own implementation w/their own (MFi licensed) products.
- In the case of non-commercial, an individual would use that version HAP* with their DIY accessory/hardware, not intended for commercial distribution.
If you're just an individual/hobbiest with z wave products, you have no use for the HAP and there is no casual way to interface w/those products. Instead, you would use the HK app to interface w/HK compatible products, in this case, your z wave locks.
If you're an individual that just wants to play with the non-commercial version HAP spec*, you'll need to tool up the hardware components and create a physical accessory on your own. See:
https://developer.apple.com/support/homekit-accessory-protocol/
If you're a dev that wants to create a HK-savvy app, see:
https://developer.apple.com/homekit/
*Purpose of This Specification
"This document describes how to create HomeKit accessories that communicate with Apple products using the HomeKit Accessory Protocol for non-commercial purposes."