Patch the plug-in into any track you like. Note that if there are no Multitrack entries on the track you will need either a dummy entry at the end of the EDL or a 'blank' sequence entry (just like an aux return). By default, the click is a 4 count with the '1' accented. This is completely programmable and will be saved with your EDL. It works just like a drum machine, with 16 segments; an orange light denotes an accented hit while a red is non-accented.
The up/down control to the right of the programming buttons allows you to set the pattern to anything between 1 and 16 beats. If you work in anything other than 4/4, you'll probably want to adjust this (i.e. 12 for 3/4, etc.) There are also some creative uses for this, such as cross-keying a gate with an odd numbered pattern for some fun polyrhythms.
The 'dyn' control on the lower left controls the dynamic variation between accented and non-accented hits. The 'thru' control controls the amount of signal passed thru the plugin; it defaults to none.
Note that Metronome will NOT track tempo map changes; this is not easily facilitated with the API.