WIFI access is available through eduroam, the world-wide roaming access service developed for the international research and education community https://www.eduroam.org.
To access eduroam you need your institution credential + the university domain, and the corresponding password. For example, my institution username is francesca.greselin so I have to use francesca.greselin@unimib.it to access eduroam. I would suggest to check if you have credentials for accessing eduroam at your home institution. See also https://www.eduroam.org/support/support_faqs/
For those who don’t have eduroam access credentials, please let us know and we will get some id for the local unimib wifi network. I need to receive from you a copy of your identity card, to prepare your access permission.