Try rotating the top right knob (has MASTER written above it) as that could be how you turn it on. I don't fly VATSIM or IVAO (I signed up but never did any flights). As you say, there is no documentation, so I'm taking a guess that it could be that. I recommend that you submit a Support Ticket so that the team can tell you what else you need to do. If it needs fixing, they will fix it. If the manual needs to be updated, they will do that. Or both!

Mark