@Dessa39 I've done this on rare occasions, when I had a not so great experience with guests and I didn't want to leave an early review as it would prompt them to leave one.
If you go into your messages page (inbox) and you pull up messages you've exchanged with this guests, the window on the right shows the reservation details. After they check out, a timer sort of starts in that window. At first, it's not entirely clear, but as the days pass and AirBnB keeps telling you to leave a review, it will start to tell you how many days you have left to leave one. As the last day approaches, it turns into hours and minutes left to leave a review. You have to keep refreshing the page to have that be accurate. It's been a while since I've done it, but that's the advice when I came to the CC to ask the same thing. I hope you can figure it out. Good luck!