Additionally, as an owner of the group, you also need to provide more info in order to make the group live
What kind of information do you think he needs to share (as a group admin)!? Do you mean he have to post his own predictions regurarely? Not sure, but I don't think this is really needed.
But you may not find professional gamblers who will share their exact tricks and strategy in your group, none will tell their secret.
Many members keep saying this. It's not true There are many
pro gamblers who will be more than happy to share their predictions, strategies, tips... if they find a friendly enough community.