verify code

You can still update your phone number but first you need to get past the verification step that is currently trying to send a text message to your landline, which cannot receive SMS. This is a common issue when an account was originally set up with a home phone.

you could try following things:

• Use the email verification option -> On the verification screen, look for “I didn’t get a code” or “Use a different verification option”. If your account has an email attached, you can verify through that instead.
• Use a recovery code if you ever saved one -> Microsoft normally allows adding a recovery code in the past. If you saved it somewhere, you can use it now.
• Use the Microsoft Account Recovery Form -> If no other method works, fill out the recovery form. Once you regain access, you can update the phone number.