Same with most Social media nowadays. Be careful
Set up the server for them and make sure they don't join any other than the one they are supposed to
There is explicit content but only if they join the server it is on. I don't use it. Nor does my son
But he does have Tiktok, snapchat, youtube, twitter. These are mostly for gaming videos and I monitor them all via his phone while he is here. And his mother while he is there!
He is almost 13.
Vigilance is the answer