Obviously, you can ask him for the review but remember if your delivered work is satisfied through the client side. If you are confident your delivered work is all right as through client requirements, then you tell the client to get a review through your work quality and communication skills.
Also, remember that the client accepts your delivered work, meaning the order is complete from both sides. Fiverr will automatically send a reminder notification to the client to leave a review of your delivered work. If the client wants or is satisfied with your delivered work they will leave you a review.