It needs the official google home thing. But you can still access the Matter controller webserver. Assuming it's the same WiFi your phone/desktop is on, you can find out what it's IP is and what the address port route should be (from their docs) and it should work.
I've had the exact same issue and still managed to add my robovac to it (running HA on an old laptop, the "controller" is just another docker service running on that laptop)