Velux windows thing definition

first of all really sorry if this is a stupid question.
I have upgraded OH to 3.0.
and now i have hard time with velux binding.
Like i said stupid question, but where on earh can i fins a serial number for a window.
I can not find anything on KLF 200.
And if i input serial number with only zeros and a name from hub, it makes Thing, and it is online, but i got no info about position.
So any help would be appreciated.

and in documentation is written:
And once the Velux Bridge is fully configured, the binding will automatically discover all its respective scenes and actuators (like windows and rollershutters), and place them in the Inbox.

but this just does not happen. only :Velux Binding Information Element is in inbox. no windows or blinds.
Any ideas ?