Rebuilding my Home Assistant (Raspberry Pi 4 Model B with HA in docker).

I have no problem adding the (now depreciated) Z-Wave integration, but I can't get the Z-Wave JS (new replacement integration) added.

When attempted to add the integration it prompts for a URL, which is pre-filled with ws://localhost:3000. But if I submit that value it gives the error "Failed to Connect". The same thing happens if I replace localhost with the pis actual IP address or with 127.0.0.1.