It looks like that link assumes that you are running the Mosquitto Broker on a windows machine which is not the case for me. I am running hassio on a Raspberry Pi 3. The Mosquitto broker addon is installed on hassio. Other than the raspberry pi running hassio, the only other machine I have is a windows machine.
Am I missing something basic here? I understand the inclination to say “read the manual” or “use google”, but when you are just starting out and don’t have a comprehensive view of how this is supposed to work, that is much easier said than done. I do appreciate you taking the time to help though.