The possibility of your iPhone XR (or any iPhone) to get a virus is extremely remote and close to Zero. You do not have a virus. Your intuition that the popup/page and warning was Fake is absolutely correct. It is a part of a scam. The idea is to get you to click on a link and then scare you to think that you have a virus among other things. After that a fee would be demanded to remove the virus (That isn't there).
Below is some more reading and information about scams and phishing -
Beware of ➔ Phishing & Other Suspicious Emails
Know how to ➔ Identify legitimate emails from the App Store or iTunes Store
Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams ➔ Use these tips to avoid scams and learn what to do if you think your Apple ID has been compromised.
Axel F.