VOIP setup


I’m fiddling around with chat systems and I’d like to add VOIP to my game. But I can’t find any documentation around how to set it up exactly anywhere. I’ve found some posts here and there that say it’s possible, that Unreal appearantly supports both steam VOIp and the opus codec. But it’s like nothing of this is official?
Some posts are talking about changing some particular ini settings to make it work. Yet I can’t find these settings inside the ini files anywhere. Do I have to add these lines manually?

I’d like to try adding a simple push to talk voip system. No 3d positional sound or anything like that yet. As far as I could find the voip system works based on the sessions system, and it even has channels I assume? Which is kind of what I’m looking for.

Anyone have any links or info that I can use to set this up?