In the event that the Key and Lock do not serialize please ensure that both are using the latest firmware:
https://helpdesk.tosibox.com/en/support/solutions/articles/2100041817-tosibox-lock-software-releases
https://helpdesk.tosibox.com/en/support/solutions/articles/2100041818-tosibox-key-software-releases
Also ensure that the Lock does not already have a Key serialized to it. This will be listed on the status page of the Lock web user interface.