This review request tool can send both email requests and sms requests to leave a review on Google for the firm. You do not need to enter both an email and phone number to complete the form. If you enter an email address, then the client will receive an email asking them to leave a review and giving them a direct link to do so. If you enter a phone number, then the client will receive a text message prompting them to leave a review.
It is important that you choose a Request Type / Interaction. This changes the verbiage that is in the email or sms asking for a review.