When you turned on two-step sign-in you received recovery codes. Each works once instead of the 6-digit code.
- Have a recovery code? Enter it on the code step. Then set up two-step again on your new phone (More → Security).
- No recovery code? Ask the house admin to reset your second step in the People list (on the web page of your box), then sign in with your password only and set it up again.
Tip: After setting up, save the recovery codes somewhere safe, not on the same phone.