[SOLVED] ID Lock 150: How to add RF Unlock key number to unlock event?

I have an ID Lock 150 Z-Wave through the Aeon Z-Stick Gen5.
The lock can have up to 9 RFID keys and 9 PIN Codes registered.
I want to know which key was used to unlock the door, so I am looking at the logging output from the Raw Alarm (JSON) channel.

When the lock is opened using a PIN code I see:


The code property tells me which PIN-code was used.
But when the lock is opened using a RFID key all I see is:


which is always the same regardless of which RFID key was used.

The ID Lock 150 User Reference Manual section 4.3 says that both Keypad Unlock and RF Unlock sends a parameter with the key used, so I guess this could be included in the unlock event too.

But… I have zero experience with OpenHAB, just installed it today. And when I try to figure were the source code for this is to be found I am at loss. There is no Z-Wave code in openhab/openhab2-addons as far as I can see?

If someone could point me in the right direction I am sure this would be a simple PR…


OK, answering myself since I just realized that the Z-Wave stuff is in a separate repo.
I will carry on there.