Thank you for the information.
Since the account does not have 2FA and since he can't receive verification codes for a password reset, the only way to recover the account is through the account recovery web form: https://account.live.com/acsr
He'll need to keep trying until he is verified by Microsoft, and he can do this up to 2 times every 24 hours.
If his Microsoft account recovery request was not granted, please review this link for tips on improving his chances of a successful recovery: https://support.microsoft.com/office/dc56c3e3-dff0-4ed5-8edb-60290eea6b53
Please be advised that Microsoft Support will not be able to grant access to any accounts.
Once he regained access to his account, I highly recommend adding three or more security info for additional verification options, such as a recovery email address, a passkey, and Microsoft Authenticator on account.microsoft.com > Security > Manage how I Sign in > Then click on "Add another way to sign in to your account"
Thank you for your understanding.
Best regards,
Darhyl