How Can i tell if I am being hacked on my iPhone?

All such messages are scams. 100% of the time, no exceptions.

Do not interact with the message or the sender. Never, never, never download anything based on a popup message.

Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

If you have not previously jailbroken the iPhone, it is not compromised.

All such messages are scams attempting to trick you into downloading some garbage app, or divulging personal and financial information. Don’t be a victim of such scams.