No longer have secondary phone # listed in 2 factor authentication, need to remove this number
Log into your Norton Account but when you enter your 2FA code, look for a Verify and go to Settings link before accepting the code. Then scroll to the 2FA settings and click on the trash can beside the device you want to remove.
Be sure you set up at least a second device/method or you could be permanently locked out of your account if you lose your primary device.
