Hi Lena
you might not know (yet) but I am Italian.... to explain something "official" in English I still find it a bit difficult....
if you mean a full view of L2 book real time streaming I believe one has to pay for it ..
doesn’t it come with your trading platform?
Sorry I don’t know who IB is…..

but I got an Italian, English and now E*Trade trading platform and they all provide me with L2 etc….
try here
E-Gate - Real Time Streaming Stock Quote Service - AlphaTrade.com
they do a 14 days trial… I think there was an arrangement with SMC (some of the SMC’s bosses got the link on their signature)
hope it help….