How do you guarantee this? And how can a user enjoy these things with granted?

It's good to hear that you are offering a no-deposit bonus for users of this forum. However, instead of doing it manually, you should create a unique link to track it where you can track how many users from this forum have created an account on your casino site. And you should create a full ANN where everything is detailed. You should also clarify how many times the users have to wager the bonus amount in order to withdraw it.

Op don't shilling this topic by creating new account and post for bonus here. I seen almost every account applying for bonus by providing their email here is brand new account. So I think this activity is very suspicious and I think all of that account are creating by you are your team. Try to do everything in organic don't try to shilling something by yourself.