How to change phone number which is not available anymore?

Question

I tried to sign in for admin with ID/PW but it shows Verify your identity as below.

However, the phone number belongs to previous office's, and this number is not working anymore.

Can we change number as current one to verify?

The previous number is +1 512 835 4900 which is registered for this account now.

Answer 1

Click on send text, and you have "sign in another way "Click on this option to explore alternative verification methods.

https://support.microsoft.com/en-us/account-billing/common-problems-with-two-step-verification-for-a-work-or-school-account-63acbb9b-16a1-47b9-8619-6a865e8071a5