Viruses on iPhone warning

Hello. Just a few minutes ago, I was on a website, doing some research, when a message popped up saying: “Your iPhone has been infected with 25 viruses by this website, click below for solutions.” (Might not be word for word, what I remembered). I didn’t click below and simply closed the tab. I was just wondering, are those messages truly accurate, or are they just a way to scam/hack you? Should I be worried about my phone actually having a virus? (Sadly I didn’t think to take a screen-shot).