Apple received a text message to change its id.

This kind of pop-up window is more common when the iPhone is unlocked and pops up directly after entering the desktop. Generally, "You must change the iPhone screen lock password within xx minutes" will be displayed, and the time is usually 30 minutes or 60 minutes.

In this case, there is no need to panic, because this is the lock screen password of the mobile phone, not the password of the AppleID account, which will not lead to the information leakage in the mobile phone. This situation may usually be due to the installation of the Apple Enterprise Services application.

Another situation is that the AppleID is locked, and you will receive this pop-up.