This year Home Assistant depreciated the old Zwave integration so now you have to either be running the HASS.io image or the Supervisor version. If you have a manual install of Home Assistant or use the version that’s available in the dietPi package manager then you need to have a separate server running. Any chance one of these could be included in the available packages?
maybe you can have a look into a Docker installation. This seems to be the fastest and easiest way https://zwave-js.github.io/zwavejs2mqtt/#/getting-started/quick-start?id=docker
On Raspberry OS/Debian, installation seems a little bit hacky https://github.com/zwave-js/zwavejs2mqtt/discussions/1216#discussioncomment-759534