For most casino bonuses, you will claim them in the same way. For a bonus which requires a deposit to be made, you can head to the cashier page and make said deposit. You may be required to enter a bonus or promo code into a box provided. If not, the bonus is likely to be triggered automatically. However, some sites require you to opt-in to promotions and bonuses. In this case, hitting the bonus button in your account will likely see you able to opt-in (or out) of several offers and deals. Failing that, contacting customer support is also a viable way to triggering (or rejecting) bonuses at online casinos. Each site has a different method, so check this out before attempting to claim a promotion.