Reviewing this topic, I do not have a raspberry pi , but I do have a Flic LR2 hub that allows my HomeKit to work. All 5 of my buttons have the ability through a HomeKit bridge to run scenes or turn on and off my HomeKit devices. The Flic LR2 hub has an ip address and this SDK interface to run javascript.
How to get a Flic button to work with docker and a Pi3 - General - Node-RED Forum (nodered.org)
I kinda understand the fact that the buttons using blue tooth connect to the bluetooth of the raspberry pi blue tooth and maybe the raspberry pi decides what to do without the use of a dedicated flic hub. But at the time I figured I need a hub for the buttons to work and they work beautifully. I assume that the flic LR2 Hub is kinda doing this for me, and somehow relaying that info to HomeKit via a bridge.
But what does the HCI do ? Now that I have gone from connection error to connected, I feel that I am close to having something working. My NS Panel does not have an IP address either, but as it is recognized as a device on SonOff iHost hub that node must register the data in a way that is recognized as I have shown pressing the one button, I am able to increase the count. I was also able to do this with Meross, but when I woke up the next morning, I realized it was counting something else. The number was up to say 35,000 counts without activating the device. Just something more that I have to study.