I received a strange iPhone notification

The message says that you don't have enough funds to make the iTunes payment. If you haven't made any recent purchases, it's likely a scam link that's attempting to trick you into entering your personal information. It's possible that your phone number was shared with a scammer, either intentionally or unintentionally, by a site that requested your number to register. In this case, it's important not to take any action except to block the user!

You can refer to this article if you need more information on how to protect your data:

Recognize and avoid phishing messages, phony support calls, and other scams

Ok, the best thing then is ignore the message.

It’s VERY easy to send a fraud text message from whatever number, it only takes a proper program, the scammer in this way can access to the same chat as your legit payment verification messages and make it seems legit since he knows what number your carry uses to communicate with you and you are most likely to trust.

Skip ahead without blocking the user :)