"Module not found: Can't resolve 'react-router-dom" +"node_modules\react-router-bootstrap\lib" code example

Example 1: Module not found: Can't resolve 'react-router-dom'

npm install react-router-dom --save

Example 2: Can't resolve 'react-router-dom'

$ npm install --save react-router-dom

Example 3: Module not found: Can't resolve 'react-router-dom'

npm i react-router-dom --save