https://pageviews.wmcloud.org/pageviews/faq/

Can I see how readers got to the page?
Referral information is not publicly available on a per-page basis. You can however see total referral statistics across all Wikimedia sites at discovery.wmflabs.org.

discovery.wmflabs.org has been decommissioned for a few years. The only public referral data we have now is specifically search engine referrals, see https://wikitech.wikimedia.org/wiki/Analytics/Data_Lake/Traffic/referrer_daily/Dashboard