MQTT generic broker

I'm trying to use a generic broker to deal with the inconsistency of the Flying Diver broker. Is it possible to substitute a generic broker? I have one installed, but can't get indigo to connect with it.
I installed the eclipse broker with the command line:

docker run -it -d --name genbrkr -p 192.168.3.20:1883:1883 -v /Users/rss/Documents/mosquitto/mosquitto.conf:/Users/rss/Documents/mosquitto/config/mosquitto.conf eclipse-mosquitto:2

The broker image is in the Docker desktop Container, and indicates that it is running.
The generic broker is not available to the Indigo MQTT trigger.
If it is possible to use this broker, what is the Indigo configuration?
Note: using ports 1883:1883 and localhost was similarly unproductive.

I can't help you with getting any (other) MQTT broker configured. When you can connect to it using an MQTT client (such as MQTTX or MQTT Explorer), then I can help with configuring the MQTT Connector plugin if needed.

That's a very nice offer.
The broker I created uses the server IP address. I was unable to connect MQTT Explorer using the IP address in the Host field, but I can connect using localhost in the Host field. Does that count?
Probably not, because even though I've subscribed to shellies/# and shellies-ng/#, under localhost, there is $SYS with 53 topics under broker, but no mention of shellies.

The Homebrew Mosquitto is now visible with MQTT Explorer.
What information do you need for the plug-in?