You tube video in question: O3DE – 003: Pong Scripting the Start Menu
At the end of the video right before tesing it intially, there’s a step missing. At 7 minutes and 26 seconds he tells you to test it and if you followed the video exactly, then it won’t work. There is a step missing. If you go back to timestamp 6:14 and look at the bottom right of the video.
Script Canvas (box)
On the version I’m working with the field is “Source”, on his screen it is “Script Canvas Asset”. You have to set this to be your Script file that you made and saved.
Update that field and save and test.