Passing information to contact field

I’ve been reading Mautic documentation about contact tracking https://www.mautic.org/docs/en/contacts/contact_monitoring.html
and it’s written:
" Mautic currently supports page_url , referrer , language , and page_title (note that the use of url and title are deprecated due to conflicts with contact fields)."

I am using tracking pixel and was wondering where can I find this information? In the timeline where the UTM tags are stored or…?

I am interested on passing referrer url to custom contact field. How can this be done?

thank you!