Telekom engineers installed this box in my apartment after I opted to switch from Vodafone following Telekom's installation of glass fibre in our building. After almost 2 years, today is the day I am supposed to start enjoying Telekom. But it has been a terrible experience. I have gone out to buy the Speed Port Smart 4 router which Telekom's customer service told me I needed. It turns out, there is no way to either connect the router to the little Telekom box or to even activate the Telekom device as the web activation code asks for a 12 or 16-digit ID which I can not find anywhere.

Does anyone know how I can solve this? 

NB: The white box besides the Telekom device is an old thingy I met in the house. It is not part of the equation.