This video focuses on blocking adult entertainment websites (apps) by using firewall categories and Deep Packet Inspection (DPI). This blocking relies on the workings of the traffic analysis feature which allows the EdgeRouter to view the contents of packets flowing through the device from LAN to WAN. This analysis is only implemented when traffic (I believe) is flowing through the firewall (WAN to LAN), so unless you have a firewall between your LAN interfaces (host to host), you will not see this specific traffic. This feature will only work for offloaded traffic on EdgeRouters other than the EdgeRouter-X (ER-X). For the EdgeRouter-X the DPI feature is supported for non-offloaded traffic. I have another video that focuses on enabling and configuring the traffic analysis feature. In this video I demonstrate blocking certain websites using the build-in categories as well as creating custom categories. The categories and apps are a Ubiquiti proprietary implementation, so we cannot add our own custom websites that we want to block. Some adult websites are listed under the Streaming-Media category. In most cases we do not want to block this entire category because it also hosts websites that do not categorize under 'adult entertainment' like YouTube and Vimeo. Before you configure this feature, you need to verify that the Topsites-Adult catogory is populated with entries. If it is empty, it might be due to the firmware version you are using, and an update is required.
Link to EdgeMAX configuration files: