Xfinity website now requires phone app verification to log in?

I logged into my Xfinity account (because my comcast email won't work on Outlook).   I input my email and password, and then it asked me via phone if this is a valid login.

My question -- what happens if my phone is lost or broken?   How do I verify this so I can log in?   Is there an alternate method to verify?

This must be something new -- I didn't used to need this to log in!