Has anyone ever gotten this pop up message on their iPhone? Is this legit?

It’s a scam. Delete it and don’t respond. See—>Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

Look at the URL: it clearly isn’t Apple’s. And DO NOT tap on “OK to repair”.

Its a browser hijacker. Please note link and do not use https://howtoremove.guide/vpn-protect-plus-iphone-mac/

It’s a malicious ad designed to scare you into downloading useless software.

Install an ad blocker.