Mqtt credentials in Docker version

Hi Folks,

I’m running a docker version of the stack using the docker-compose definition from here: https://github.com/brocaar/chirpstack-docker

I want to connect to the stack with @iegomez device simulator, but I can’t get the mqtt connection to work,

In the logs I see:
mosquitto_1 | 1597855587: New connection from 172.20.0.1 on port 1883.
mosquitto_1 | 1597855587: New client connected from 172.20.0.1 as lds-1597855587940988557 (p2, c1, k30).
mosquitto_1 | 1597855587: Socket error on client lds-1597855587940988557, disconnecting.

which I think might be an authentication issue, but I have the user and password both set to “” which seems to be the configuration values from chirpstack-gateway-bridge.toml in the docker-compose repo.

Can anyone tell me if those are the correct default credentials, or how I can check / find them please ?