Can you tell us your project name?
you’ll need something like
"start": "node index.js" instead of
"start": "index.js". it’s a little complicated to explain, but “command” means something very specific here called a “binary” if you want to look that up, and “found” also refers to a specific set of locations collectively called the “PATH” where it looks. you might be a little busy with node.js to delve deep into this sysadmin-related stuff right now, but it could be useful to know later.