Get the EUI of the communicating devices

Hello everyone!
I need to retrieve the device EUI of the devices communicating through my gateway (RAK7243).
I need the EUI of all devices, both already added to the network and application server and the ones not already added.
Can you describe me a way to collect this information (from the MQTT broker or some log file…) ?
Thank you very much!

Unless the gateway receives a join-request (which contains the DevEUI), this information is not available as devices use a DevAddr for identification. Only the ChirpStack Network Server knows the DevEUI after is successfully validated the MIC.