I see Sam already answered your question. It can take up to 6 days but I had one post on the same day.

Hi, Tammy. Cash back rewards are not immediate but will automatically show up in your CouponCabin account within 6 days of your purchase once the store notifies us of your transaction. It's important to note that all stores report cash back to us differently, and while some stores may report orders to us on the same day, most take between 4 and 6 days.