Sending JoinAccepts to Gateway Bridge [MQTT]

Hi guys and girls. Thanks for all the amazing work :grinning:

I am currently working on a custom solution where we would like to use only the gateway bridge and not the rest of chirpstack.

So the bridge is setup to use MQTT, and I subscribe to those topics and receive the JoinRequests as they come in.

But to what topic should I publish the JoinAccepts on for the Gateway Bridge to correctly pick them up and send them back to the devices?

I hope the question makes sense, otherwise I would be happy to elaborate.

Downlinks are sent on the ...../command/down topic.