How to design a review system without actual booking?

Hi, I'm building a website to help people find accommodations based on a specific theme. However, there will be no booking system, but I still want to have some kinds of reviews. My first idea was to guests to write their reviews and put their reservation number and date of stay before being approved by the host to show review. However, I feel like this idea isn't that great because of fake account that could be created, or host just declining all low reviews. Now, my idea is to get the reviews reviewed by