Know GatewayID when using docker image for Raspberry Pi

Hi,

I have used the docker image for Raspberry Pi for installing chirpstack gateway bridge.
I was able to run the docker image on Pi.
But I don’t find how to know GatewayID to add in ChirpStack Application server.
Please let me know how to know the GatewayID from docker image/how to configure GatewayID.