ZyXEL Communications USG FLEX H Series User Manual page 268

Set the block list log action to log alert.
4
Click Add to add a block list rule using the parameters given in
5
Click Apply to save your changes.
6
Go to Security Policy > Policy Control. Select LAN_Outgoing then click Edit.
7
Chapter 16 Content Filtering
USG FLEX H Series User's Guide
268
Table 134 on page 267.