Configuring preferences and options in Outlook.com
Hey there! Nice to meet you!
Unfortunately, Microsoft has recently phased out the option to add a phone number to a Microsoft account, as stated in this article, particularly under "Notes": https://support.microsoft.com/accounts-billing/manage/microsoft-account-security-info-verification-codes
However, you can add other verification methods, 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"
Please feel free to let me know if you need anything else.
Best regards,
Darhyl