The [[availability_topic]] section
This configures a topic that MQTTPublish uses to publish its availability ‘online’ or ‘offline’. Under the covers MQTT LWT function is leveraged for ‘offline’ messages.
enable
Turn the availability topic function on and off. Valid values are true or false. The default value is true.
topic
The topic that the availability messages are published on. The default value is status.
online_payload
The default value is online.
offline_payload
The default value is offline.
qos
The quality of service level to use when publishing the messages.. The default value is 0.
retain
If set to true, the messages will be set as the “last known good”/retained message for the topic. Valid values are true or false. The default value is true.