Select Options... from the View menu.
Select the Connection tab, make sure the Access the internet using a proxy server setting is checked, and click on Advanced... .
If the HTTP proxy is already specified, and the Access the internet using a proxy server box was checked to start with, then you need to write down the host and the port that it is set to use. Later you will use these to tell WebMask about this existing proxy.
Set the HTTP proxy to use address 127.0.0.1 and port 8080.
Setting up your browser to use WebMask