How to determine in PHP that the user came to the site from facebook or instagram ads?

Question

PHP

How to determine in PHP that the user came to the site from facebook or instagram ads?
PS: Yandex Metrica and Google Analytics somehow determine this, but I need to do such a check on the server (do not offer UTM tags)

Answer 1

In what sense utm not to offer? This is the only reliable way to find out about the user. You make a link from utm to the handler page, then you send it to the main portal.

Answer 2

https://developer.mozilla.org/en-US/docs/Web/HTTP/...
Is this?

Answer 3

Doesn't a simple http_referrer solve your problem?

Answer 4

Wait, after all, the facebook offers a "pixel" that counts clicks from ads... This is a script, in my opinion, put in and hello)