How to find your number if you forgot you activation lock information
How to find out your phone number if you forgot your activation lock information
iPhone SE, iOS 11
How to find out your phone number if you forgot your activation lock information
iPhone SE, iOS 11
I'm not sure what your phone number has to do with activation lock, but maybe this article will help:
Turn off Find My iPhone Activation Lock - Apple Support
Or maybe this is what you are talking about:
How to unlock your iPhone for use with a different carrier - Apple Support
How to find your number if you forgot you activation lock information