Virus malware protection for iPhone

None. There are no viruses in the wild that can infect an iphone that has not been jailbroken. All apps in the App Store have been vetted by Apple. There is no malware. Don’t install apps from outside of the App Store.

Can't speak for Apple, but the experts on this support site do not recommend that you install any kind of malware or anti-virus software on your phone.

The iOS system provides all the protection that you need and 3rd part software often interferes with the iOS system, actually making things worse, not to mention wasting your money.

Frankly, even if the app were free.......it would still not be worth the price.

None! You do not need any malware virus protection on your phone and any email/message you see that says you need protection is a scam. Any app you see that claims it can scan your phone for protection is also a scam.