How can I know if my iPhone 13 mini has been compromised?

Your phone was not hacked, it is a scam message designed to get you to purchase unnecessary software or phish for personal information.

Read more about it here -

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

You've not been hacked. This is a very common scam. Do not reply, simply ignore this message.

A non-jailbroken phone cannot be hacked. What you got was a scam message. Ignore it.

You're very welcome!