mosquito broker port adress ?????

My question is how I am able to see my mosquito broker working or not ???
In my device I have following software installed from dietpi software. so by default system gave internal LAN address as :-

Pi Hole (http://192.168.1.64)

Plex server (http://192.168.1.64:32400)

mosquito

FTP server

Home Assistant (http://192.168.1.64:8123)

In mosquito FAQ there is not any port mentioned for mosquito broker. As http://192.168.1.64 LAN address already occupied by pihole. So in my application side I have to define mosquito broker IP address also if any port . default address will go to pihole not to mosquito broker, is it possible I can define port for mosquito broker like (http://192.168.1.64:1823). So that my mosquito needed application diverted directly towards http://192.168.1.64:1823. Please advice also tell me how I can confirm that mosquito performing his duties, in HTOP command I am able to see that mosquito service is working. thanks