Is there a way to get a text list of all the sites b being filtered
Filtered by what?
Intrusion Prevention System (which ruleset(s) and which rules selected) or
IP Blocklist (which blocklist(s) selected) or URL Filter?
URL’s that are potentially being filtered via IP blacklist or the URL filter
To find the specific url that is used for the IP Blocklist(s) that you havce selected, you can find it from the sources file.
You can read this directly on your IPFire from the command line
/var/ipfire/ipblocklist/sources
or you can look in the same file in the IPFire git repo
This file contains the details of each IP Blocklist and the entry marked url is the location of the list used.
Be careful when downloading the list to look at it. That will count towards the download rate from your IP. If you do it too frequently, your IP might get blocked by some of the lists.
Also if the download rate is once per day for a specific list, then once you have downloaded the list IPFire will not be able to update the list until a further day has gone by.
For the URL filter there is only one download list available and that is from the University of Toulouse and there is a link to that source in the IPFire documentation for the URL Filter.
https://www.ipfire.org/docs/configuration/network/proxy/url-filter#automatic-blacklist-update