It is a hostless apartment! In order to enter the apartment, you have to either pay 15 EUR to get someone to meet you at the apartment address to leave you the key or go to an Hostmate office outside Milano central station to get the key.
Sincerely, and being in many AirBnbs, never happened to me to have to do either of those. The host believes that every guest arrives at that station when it could easily be not the case, as is my case that I was already in Milano.
I complained about it and the host didn't like it so she started reproaching me about that I complain a lot, that she did arrangements to let me check-in at 11 (when I explicitly requested it when booking and she approved it), etc.
In summary... all good with the apartment, not good with the host and the entrance method.