- Click the FoxyProxy icon in the upper-right of the browser. This opens the FoxyProxy Options dialog.
- Click the Add New Proxy button on the FoxyProxy Options dialog [screenshot].
- Select Manual Proxy Configuration. Enter the Host/IP address and port number of the proxy server. To get a proxy IP address and port number, click here. Click the OK button and click it again when asked about whitelisted URLs.
- Change FoxyProxy's mode to Use proxy "New Proxy" for all URLs [screenshot]
- That's it! You should test that you're now using the expected IP address.
For a more detailed guide on configuring FoxyProxy, read this.