You can only rate or review products from the Facebook for iPhone or Android app. 

You cannot rate or review products from a computer or mobile browser.

To rate or review something that you purchased on Facebook:

1. From the Facebook for iPhone or Android app, go to your order history in your Facebook Pay Activity.
2. Tap the order for that item, then tap the item name below Item details.
3. Scroll down and tap Write review.
4. Tap the Star icon to choose a rating from 1—5.
5. To include a photo, you can tap the camera icon.
   You can also enter text to add a review.
6. Tap the Send icon .