Players, coaches and moderators: The tournament director should provide directions in the #announcements channel on the Discord server about who to contact if something goes wrong. Generally, you’ll want to do an @mention of that person in the #general chat to get their attention because they may be in another channel.
In extreme cases, you may want to @mention an entire role in the #general if you need help. For instance, an @mention of the @Control Room role.
You should also consult here for how to troubleshoot common Discord online tournament issues.