1. Go to Apple menu -> System Preferences
2. Click the “Advanced” button
3. Select the “Proxies” tab.
4. To manually configure a proxy, you’ll need to enable one or more of the “Web Proxy (HTTP)”, “Secure Web Proxy (HTTPS)”, “FTP Proxy”, “SOCKS Proxy”, “Streaming Proxy (RTSP)”, and “Gopher Proxy” checkboxes. Enter the address and port number of the proxy for each option you enable. If you were provided with a username and password for the proxy server, enable the “Proxy server requires password” option and enter the username and password. If you don’t want to manually configure a proxy, ensure all these boxes are unchecked.