Mosquitto MQTT broker What IP/domain should i set in my arduino?

I am trying to setup an homemade MQTT sensor on NodeMCU.
I have installed the Mosquitto MQTT broker from det tab.

This is my config:

  "plain": true,
  "ssl": true,
  "anonymous": true,
  "logins": [],
  "customize": {
    "active": false,
    "folder": "mosquitto"
  "certfile": "fullchain.pem",
  "keyfile": "privkey.pem"

What address should i set up in my Arduino code?

And port 8883

Is not working for me.
What is the obvious thing that i have missed?

You need to use your LOCAL INTERNAL IP address for your HASSIO pi. If you use your external public DNS name, you are defeating the purpose of a LOCAL MQTT instance…

Haha. I see.
That makes sense!

Thanks for the answer to my noob question! :slight_smile: