These settings are found in Admin UI at Squid / Auth / Captive Portal node, tab General Settings as shown on the following screenshot.
Activate Captive Portal
Enables or disables Captive Portal. By default, Captive Portal is disabled. Note it is not possible to use Captive Portal with another type of proxy authentication.
Specifies IP address or fully qualified domain name of the proxy machine. If left blank (default) the portal code tries to determine the IP address or domain name of the proxy machine and uses it in portal redirection page at
/opt/websafety/etc/squid/portal.html. Note this setting might be very important if your proxy machine has several network interfaces (IP addresses) assigned. It is also important if you use your own certificate for the HTTPS access to the Admin UI - this must then match the name present in the HTTPS certificate.
After a user is successfully authenticated to Captive Portal - his IP address and user name are written to the session database in
/opt/websafety-ui/var/db/portal.sqlite. The expire duration setting is used to automatically purge the records from that database forcing the users to re-authenticate after configured number of minute elapses. By default, this is set to 60 minutes but it might be advisable to set the limit to 8 hours (480 minutes) to minimize re-authentication needs during a working office day.