I was scratching my head trying to extend the task bar to my secondary monitor. I needed to create another panel (right click -> new panel), drag it to the required monitor and then position it as I wanted (right click -> properties -> orientation).
Getting the open windows to show up in the task bar needed to be enabled also (on both the main and new task bar panels). To enable this: right click -> Add to panel -> Search for “window list” and click add.
Now the panel on each monitor will display the applications/windows you have open on each monitor, they will even move between the task bars if you drag the windows between each screen.
I got my window list info from this blog: