Notice of Trojan Virus on my IPHONE 14 Pro Max received when I tried to open Facebook

Don't give in to Phishing

Keep the iPhone updated to the latest iOS always and never Jailbreak. That's it.

iOS / iPadOS devices cannot be hacked or infected with Virus / Malware / Spyware unless you have intentionally downloaded spurious software or unauthorized apps directly from the internet and installed them on your device or/and have Jailbroken. 

It (Hacking) also depends on how careful you are in sharing sensitive and valuable information pertaining to your iPhone such as Passcode, Password, etc with your friends and family members.

Be judicious when sharing the device's sensitive and valuable information with friends and family members.

If you don't reckon what is said above is true then you have two options...

1. Report the hacking incident that you are facing to the local law enforcement authorities and follow it up
2. Believe it, it can't be hacked. There are people who still believe that the earth is flat and also some believe no one has ever landed on the moon. What can anyone do about that? This is a free world you can believe in anything, the choice is yours.

No, all such messages are scams presented by criminals. Close the offending page and avoid sites that are involved in such bogus advertising tactics. Do not download anything based on such bogus messages.

https://discussions.apple.com/docs/DOC-8071

No. this cannot be legit. It is phishing.

You are welcome.

Stay alert.