I just purchased the device and when i am trying to setup and scan the bar code, it says the device is registered under someone else.
Did you buy it in a store? That only happens if someone else used it before you. Could have been a return or possibly stolen. Once to link it to you it can’t be used by anyone else unless you respond to the email you will receive as the owner asking for you to give up ownership.
It’s a great security feature since these devices are not cheap.