The IPv6 feature can be activated from the Central app that you have installed on your Android or iOS phone.
The phone with Central app installed on it must be connected to the Bitdefender BOX network in order to enable or disable IPv6..
Just go to your Bitdefender BOX Network settings menu, and locate the IPv6 setting (it is set to off by default). Note that, upon enabling the feature, the devices will be shortly disconnected, in order for the setting to be applied. When the devices are reconnected to the network, they will receive one or more IPv6 addresses along with the IPv4 one.