How to subscribe to a topic

[rwb196884]

I'm trying to connect to MQTT and receive messages.

PubSubClient is broken and dead , Espressif's mqtt_client example doesn't even compile, and MQTTClient simply doesn't work; this is next on the list.

But the example https://github.com/cyijun/ESP32MQTTClient/blob/main/examples/HelloToMyself/HelloToMyself.ino makes no sense: the functions onMqttConnect and handleMQTT are defined but never used.

Is it possible to use this to subscribe to a topic and receive messages? How?

Somehow handleMQTT is getting called, but it's unclear how to get the topic or payload.