Although this question is already answered but I am bit new to WordPress and PHP so after an order is completed customers can write a review multiple reviews. I want that customer only reviews one time on every product per order.

For Example
Let suppose in Order 1234 Customer reviewed on Product A and B only one time. Now he can only review again if he placed order of that Product again

In this post
How to limit users to one comment per post

I have seen a code but don’t know where to place this. Thanks in advance