Trying to follow this video in pico-8 but using player or io.read doesn't highlight or do anything. What am I doing wrong?

Hey all! Just purchased PICO-8 couple days ago, really love its aesthetics! Anyways, I bought PICO-8 because of my prior knowledge with music trackers/sfx creation and pixel art. I actually use programs like Aseprite(Retro/Pixel Animation Studio) and Milky Tracker (Digital Audio Workstation) on a daily basis! Ever since I was just a wee lad I've always had game ideas bouncing around in my head. Even back in 2008 I was using a tool called Lunar Magic to hack Super Mario World to use the pre-existing engine to modify levels and the overworld. With all this said I've never written an original line of code in my life. I was going to spend the afternoon with my face full of those picozines and try and learn from there. While regularly consulting the manual as needed. But is there anything I should know?