Polybar is part of Herbstluftwm but it can be used on any tiling window manager.
The code is to be uncommented from the file in ~/.config/polybar/launch.sh to get a second polybar.
But when making this video we had not thought about users wanting to have a second polybar so the video includes the search for a solution.
There are two commands you need to investigate
Use help or man or TAB to figure out what to do.