Virus

Your phone can’t get a virus. All messages that say it has a virus are scams to steal your identity or talk you into spending money on useless (and sometimes dangerous) apps. And all virus blockers that claim to be for iPhones are useless also.

See this Apple support article→Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

How is the iPhone notifying you that you have a virus on it? It is nearly impossible to get a virus on the iPhone unless that iPhone was Jailbroken. What is the exact message that you are seeing and how is it communicated to you?

Axel F.