“code .” is not working in on the command line for Visual Studio Code on OS X/Mac

The command code . doesn’t work in this manual.

All the other steps before that worked. How can I call the Visual Studio Code in an OS X terminal?

pwd

/Users/mona/nodejs/myExpressApp

code .

-bash: code: command not found

I ended up opening it from within Visual Code Studio by changing the workspace, but why won’t that command code . part work?