Run inside your project:

npm i --save @fortawesome/fontawesome-free

Add to file app.scss

@import '~@fortawesome/fontawesome-free/scss/fontawesome.scss';
@import '~@fortawesome/fontawesome-free/scss/regular';
@import '~@fortawesome/fontawesome-free/scss/solid';
@import '~@fortawesome/fontawesome-free/scss/brands';

Run in command line:

npm run dev