How to make ROS Node talk to IoT middleware?

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I have an open source IoT middleware setup on my local network(on a separate machine). Imagine it to be a server that opens up certain ports to listen data

How do i make a ros node running locally on my machine send data to an IoT middleware (running on a different machine, but local to my network?

Below you can see, a client call to send messages over a channel (similar to a ROS topic). Basically i would like to replicate the below operation using ROS nodes.

POST /https://10.0.0.126/http/channels/<channel-id>/messages with <device-key> as authorization token?

My local machine - ROS Melodic, Ubuntu 18.04 LTS IoT middleware - ROS Kinetic, Ubuntu 16.04 LTS

P.S - The IoT middleware already supports HTTPS, CoAP, Websocket and MQTT. protocols and exposes various ports to send and receive messages. See link for more info on the middleware IoTMiddleware