Set the proxy server password.
It is possible to make your own custom proxy server. In that case you might want to password protect it and then your Unity players must set this value appropriately.
function Awake() {
// Set custom proxy server address and password
Network.proxyIP = "1.1.1.1";
Network.proxyPort = 1111;
Network.proxyPassword = "secret";
}
no example available in C#