How to Require Moderator Approval for Posts in Your Facebook Group
By default, any member can post anything they want in your Facebook Groups. This means they could post horribly offensive content, and while you can remove it, it might be a while before you get to it.
8 Sep 2017 ... Scroll down and under Post Approval, check the box that says All Group Posts Must Be Approved By an Admin or a Moderator, then click Save.