I got a pop up that said my iPhone was hacked

All such messages are scams presented by criminals. Close the offending page and avoid sites that are involved in such bogus advertising tactics. Do not download anything based on such bogus messages.

Phony "tech support" / "ransomware" popup… - Apple Community

The popup is a phishing fraud. You are safe to ignore it. You are NOT safe to follow any of the links it offers, or enter your credit card or bank details to make a purchase. That is what the scammers really want, your card or bank details so they can empty your account.

The bottom line is that any popup reporting a security breach or virus is a scam.

Note that "phishing" e-mails, Web sites, Web notifications, and so on may use familiar graphics to try to fool you.

For instance, criminals may place a copy of the System Settings icon in the custom icon field of a Web notification to make it appear that their bogus "You've got a virus!" or "You've been hacked!" message is from your iPhone or your Mac. You can put lipstick on a pig (or a scam) – but even with lipstick on, a pig is still a pig.

This video shows the degree to which criminals will go to try to scam you out of your money. Unfortunately for the ones here, they called a police captain who knew all of the tricks.

I love how she laughs at them (silently) while illustrating how NOT to be scammed. (But if you get phone calls like this at home, the best thing to do is to just hang up.)

YouTube – Apex, NC Police Captain Toys With Phone Scammer