Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello Dr Mohamed Nour EIDin
Thank you for contacting the Microsoft forum community, it is a great pleasure to work with you in the above consultation.
If i understand you correctly you would like to make changes to your phone number in the email under account alias, please correct me if that is not the case, if so, you can make this change by following the steps below
The available option is to update the setting via security information
Go to your security settings and remove the old phone number. This can usually be done by navigating to the security info section of your account settings and selecting the option to remove the old phone number.
Add or remove an email alias in Outlook.com - Microsoft Support
Look forward to your update regarding the above issue to further understand your query.