MQTT seems to have become the defacto protocol for passing information between the various parts of a IOT system, the acronym stands for MQ Telemetry Transport, MQ was an IBM product range, possibly Message Queue.

encrypted MQTT listens on 8883, plain 1883.

Introduction to MQTT:- https://www.hivemq.com/blog/mqtt-essentials-part-1-introducing-mqtt/

Setting up MQTT with Mosquitto:- http://www.steves-internet-guide.com/mqtt-username-password-example/

MQTT explorer for Linux http://mqtt-explorer.com/

Growatt Grott server https://github.com/johanmeijer/grott

Display software and hardware
https://www.openhasp.com/0.7.0/
https://www.aliexpress.com/item/1005006348529558.html