Hello, this is Emily.
If your iPhone didn't store a backup copy for you, then this can be a bit challenging.
On the page asking you to enter your code, or confirm code on the app, choose "I can't use the app now", next, if applicable, you can click "show more verification methods" to see if you may have another contact method you can use. If not, select "I don't have any of those." This will start the process of adding another contact method. The only challenge is that it will require a 30-day wait before this change goes into effect. This 30-day waiting policy is intended to protect users whose contact information has been changed by someone else so that they have enough time to reverse the change. This is a security policy that no one can bypass unfortunately. You can read about this policy here:
https://support.microsoft.com/account-billing/-....
