@Abdul_ann
Your son's account was previously accessible? And he has not activated the new sim card but needs to swap sim cards in his account? Click on "Didn't get code?" And choose "email" instead.
If he cannot access his email to get the code and he still has active service he can choose "voice call". Then call his phone # and enter his voicemail PIN# when his voicemail picks up. The 6 digit code can sometimes have the first digit cut off so wait for the code to be repeated a second time to copy it down then enter it in the login prompt. Erase the voicemail message containing the code immediately.
Once logged in he can swap sim cards on his profile page. He may need to reboot his phone if he didn't power it off to insert the sim card.
