If possible, hold on to your old phone so you can transfer the passkey to your new phone. If you get a new phone and don't have access to the old one, the IT Help Desk can assist with removing the security requirement which will allow setup of a new phone.
If your phone is lost, damaged, or stolen, you will need to get a new or temporary phone with at least a phone number that can receive text verification to be able to use multifactor authentication. If you do not have a YubiKey set up as a back up, then you will be locked out of your account until your phone is replaced.