How to add a domain to be blocked by Privoxy?

[amosshapira]

It looks like some spam domain (paulty.com) is not blocked by Privoxy.
The "Edit" button in Privoxy's GUI is disabled because the CGI editor is disabled, according to the privoxy's status page:

The CGI editor is currently disabled, thus no edit buttons are shown.
Please have a look at the enable-edit-actions documentation to learn how to enable it and what the risks are.

(and besides, I need to add the configuration in a way that will survive a container restart).

It would be nice if there was an option to pass through an override of privoxy's user.filter, or some other way to add missing domains to the block list.