I downloaded the a command line utility from this github webpage . I clicked on the green Clone or Download button to download the zip file. Although, there are also files that can be downloaded from the releases tab. I'm not sure whether I'm supposed to download those files instead. After downloading and unzipping the zip file, I double-clicked on the file entitled displayplacer, which opened a terminal window that ran a bunch of commands.

Now what? How do I use this program?

I tried opening a new terminal window and running displayplacer list which, according to the github page, is supposed to Show current screen info and possible resolutions. However, the terminal window returned zsh: command not found: displayplacer after I entered the command. Did I not install the code properly???

Ultimately, what I want to do is set up a keyboard shortcut that switches the primary display between my macbook's internal display and my external display. How do I do this???

(macOS catalina)