How do I choose a poker union to join my club?

Hi , guys! I have a small poker club. I organized it to make an online game and have a small income. I've read that there are poker unions. Each league has its own conditions, fee, access to various games and tournaments. I want to attract more players to my club, and in order for them to stay at my club longer, I have to give them more variety. I contacted one union, they have these conditions:
security deposit - 400$
cashback - 10% on winnings plus rake
Dynamic Union Fee - 2% to 15% (If the club's players lose a lot, the fee will be lower.)
and they will help me connect my players to their online platform.

Can you tell me, has anyone had any experience joining a poker union? Are these normal conditions for the club? If you are a club-host and you are a member of the union, what are your conditions in the union?