Enter your account name and password in the Username and Password fields. Select the “Proxy server requires password” checkbox if the proxy server is protected by a password. Select a proxy server, such as FTP Proxy, then type its address and port number in the fields on the right. If you want to configure your proxy settings manually, do the following: If your network administrator provided you with the address of a proxy auto-configuration (PAC) file, select Automatic Proxy Configuration, then enter the address of the PAC file in the URL field. To automatically discover proxy servers, select Auto Proxy Discovery.
If you want to configure your proxy server settings automatically, do one of the following: In the list, select the network service you use-for example, Ethernet or Wi-Fi. On your Mac, choose Apple menu > System Preferences, then click Network.