Home Assistant - MQTT 
I admit that I am not familiar with MQTT and Home Assistant and I need some help:
In the following code:
...
const char* mqttServer = "192.168.1.200";    _**The domain or IP where the MQTT is installed (namely the IP of Home Assistant)?**_
const int   mqttPort = 1883;    // MQTT server port
const char* mqttUsername = "user";  // Optional, leave blank if not required **_Username of HomeAssistant or MQTT?_**
const char* mqttPassword = "pass";  // Optional, leave blank if not required _**Password of Home Assistant or MQTT?**_
...

Is there something I have to change on yaml code (except of course the configuration of zones, partitions etc.)?