How to get rating from facebook page?

Question

Facebook

Good day!
After a long search, I still don’t understand how you can pull out, let’s say, the rating of an institution (stars) from a Facebook page. Smart people suggested that this is easy to do through the API, I'm afraid I don't have enough brains. In general, you need to put ratings from Facebook from different pages on your site, and so that they are updated depending on subsequent votes on Facebook.
Thanks in advance!