Can’t retrieve referrer URL

I’m trying to get the referring URL for my form submissions as I have my form on various pages and I’d like to know which pages are being used more than others.

Followed the instructions here: https://docs.gravityforms.com/capturing-the-http-referrer-url-on-form-submissions/

Added the function and then created a hidden field for both slug and value using ‘refurl’ as the value of each and I just get refurl as the result. Obviously, not what I want. Why can’t I get my referring URL?

https://veilcosmetics.com/fr/makeup-cosmetics/light-foundation/#tab-shade_tab