Flux, an extensible language used by InfluxDB 2.0, was extended to write data from InfluxDB to MQTT using the `to()` function with an MQTT extension, allowing users to send data to an MQTT broker for IoT applications, with a custom configuration of options such as broker URL, topic, message, and quality of service. A task in the InfluxDB 2.0 UI can be used to create a Flux query that writes to an MQTT broker using this new functionality, which has been submitted as a pull request but is now part of the master branch, awaiting release. The MQTT output allows users to send data from InfluxDB to IoT devices for real-time monitoring and control, with options for message formatting and quality of service.