Licence number for beta unit

I have a beta unit of the herelink Hx4-06075. I have recently made a firmware update and the screen asks for the Product Key. Where can I find it? there is no such Key on any device/box.
Anticipating the answer, no I’m not going to contact my distributor as he turned out to be unreliable. Can someone from Cube contact my by email? And why email support isn’t available anywhere on the page anyway?

Your retailer is the correct place to get this key as they have been provided what is necessary already.

The process is to contact them, who are they ?

@Michael_Oborne fyi.