Trying to set up react.js environment, not working

I used a tutorial from https://www.tutorialspoint.com/reactjs/reactjs_environment_setup.htm

got below message from command prompt when i entered "npm start" I did everything and i have node.js installed. PLEASE HELP!!

edit: wjwar is username

C:\Users\wjwar\Desktop\reactApp>npm start
> reactApp@1.0.0 start C:\Users\wjwar\Desktop\reactApp

> webpack-dev-server --mode development --open --hot
‘webpack-dev-server’ is not recognized as an internal or external command,

operable program or batch file.

npm ERR! code ELIFECYCLE

npm ERR! errno 1

npm ERR! reactApp@1.0.0 start: webpack-dev-server --mode development --open --hot

npm ERR! Exit status 1

npm ERR!

npm ERR! Failed at the reactApp@1.0.0 start script.

npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:

npm ERR!     C:\Users\wjwar\AppData\Roaming\npm-cache_logs\2019-02-27T06_01_00_391Z-debug.log

#node-js #npm #reactjs #webpack