With YITH WooCommerce Review For Discounts, you will be free to offer a coupon to all users writing a review about the products they have purchased. Once they leave a review, the system will automatically send an email with a coupon code they can use on the next purchase.
In combination with YITH WooCommerce Account Funds, the admin can reward the registered customer that leaves a review also with funds.
After installing and activating both plugins, you will be able to configure the email that will inform the customers about the new funds that have been credited thanks to their review.
For further details about YITH WooCommerce Review for Discounts, please refer to the official documentation.