Notification from Apple
Hi, my notification when resetting my Apple ID is not coming through on my phone from Apple. Everything else comes to and from Apple perfectly fine. Thanks.
If you only have one device the verification is done in the background.
If you use iOS 11.3 or later on your iPhone, you might not need to enter a verification code. In some cases, your trusted phone number can be automatically verified in the background on your iPhone. It’s one less thing to do, and your account is still protected with two-factor authentication.
Get a verification code and sign in with two-factor authentication - Apple Support (IN)