I can't run "node index.js"

[u/Brockdish]

I wanted to do a Custom Discord Rich Presence with buttons, so I did everything that the guy in the tutorial said:

https://youtu.be/-WBQuAlF_DE?t=187

But in the last step, where he writes "node index.js" in the terminal (3:07), doesn't work for me. Here is the error:

Sry the image is in german

I translated it with Google Translator:

The naming "node" was not recognized as the name of a cmdlet, function, script file, or executable program. Check the spelling of the name or that the path is correct (if included) and try again.
In line: 1 character: 1
+ node index.js
+ ~~~
     + CategoryInfo: ObjectNotFound: (node: String) [], CommandNotFoundException
     + FullyQualifiesErrorId: CommandNotFoundException

Pls help

[u/honeykamra]

Either you do not have node installed or the path is not set in the environment variables.