./src/index.js Module not found: Can't resolve 'App.js' in 'D:\rrrrr\awesome\src' code example

Example: ./src/index.js Module not found: Can't resolve 'App.js' in 'D:\rrrrr\awesome\src'

./src/index.js
Module not found: Can't resolve 'App.js' in 'D:\rrrrr\awesome\src'