Apple does not endorse or recommend any security apps.
It is not necessary to install security apps on your iPhone. They actually get in the way of the iPhone's performance. The chances of your iPhone getting hacked are almost zero. Most (if not then nearly all) of the claims of a hacked iCloud account are related to compromised Apple ID credentials through a scam and not through hacks.
It is probably worth your while to understand and defeat scams rather than install a security app which is not necessary on an iPhone or even a Mac for that matter.
Axel F.