How to use keystrokes to display on your secondary extended screen?

Hi:

I’m using 2 screens with my macbook. one is the normal 1366px width screen, the second is the 2370px width screen.
I’m planning to create some videos using my secondary screen. Unfortunately, I can’t find any any option to do it. I’m happy with the mouseposé clicks. It’s just this keystrokes that I need help with. Can you let me know if there is such an option?

I’m using macOS High Sierra 10.13.4.

Thanks in advance,
philcyb

+1, this would be really great

+1 me too