Hello Eslam mohsen Abdalaah,
Good morning!Thank you for posting to the Microsoft Community. We are happy to help you. According to the description you shared, we understand that you can't log into your college student account because your account was registered with a number you no longer have. Correct me if I'm wrong, please. Regarding your query about you lost your phone number that is linked to my college student account, so you can't log into the college student account because it asks for the code from the phone, but I don't have that number anymore. Base on the screenshot i can see that your college account has been link to only one authentication method.
As you said that with the lost number the login option always gives 3 options to choose from, the option can be:
1-"Approve a request in my Microsoft Authenticator app" or
2-"Use a verification code from my mobile app."
3-Text xxxxxphonenumber
Since you have lost your number, you cannot use the only option you have.
Please try signing in to the Microsoft 365 (office.com) portal.
- Select your avatar in the upper-right corner and select View Account.
- Under Security info , select Update info.
Or, depending on how you use multi-factor authentication, there are a few places where you can change your settings, such as your phone number.
- Log in to https://myapps.microsoft.com
- At the top, select profile.
- Select Additional security check.
- This will take you to the page that will allow you to change your settings.
In the case, you can't perform one of the steps above that means your organization doesn't allow users to change their authentication information on their own, so you need to contact your administrator or IT department to update the authentication method for the affected account. Reference: Manage authentication methods for Azure AD Multi-Factor Authentication - Microsoft Sign In | Microsoft Learn. Your organization has configured this process for your organization's security. Please feel free to let us know if there are any questions or if we have misled you. We will continue to assist you based on the information you provide. We sincerely thank you for your
patience and cooperation.
SincerelyEben Ezer Tres | Microsoft Community Moderator