The HT-M00 is not a LoRaWan gateway and so must not be connected to TTN, as doing so would cause problems for other users and not just yourself.
What it is, is an evil hack using two node class radios, and as such is confined to private non-TTN experiments only. It lacks the hardware needed to participate in the community network, and so it is not permitted to register or connect it to that.
It would really be best to return it to the vendor, since it has no real practical use.