Guide to configure GenieACS to use STUN server

HI all… Is there a guide to configure GenieACS with STUN server? Current, some of our devices are running behind NAT and they’re not reachable from the Genie server. I’d appreciate if someone can give a guide on how to go about this. FYI, i’m using GenieACS 1.2.7 version on Ubuntu.

Thanks