./node_modules/react-scroll/modules/index.js Module not found: Can't resolve code example

Example 1: module not found: can't resolve 'react' in 'c:\users\pavlos\desktop\reactjs\hwr\reactproject2\src'

type:  npm install react
next command type : npm install react-dom
that's the solution.

Example 2: Module not found: Can't resolve 'react'

npm install react
npm install react-dom