How to use "Linkify text url" ? Rated 5 out of 5 stars

This addon is just great; but I wonder how to use the "Linkify text url" feature cuz it seems to not work for me - no clickable links at all. So could anyone can show me how? Thanks. :)

This review is for a previous version of the add-on (4.7.8).  This user has a previous review of this add-on.