Setting up vuetify by clicking yes for fontawesome 5 trying to add fas fa-*** it's not works because in main.js the import '@fortawesome/fontawesome-free/css/all.css'; is not added so do it manually by adding it and install it by
for linux user:
sudo npm i @fortawesome/fontawesome-svg-core @fortawesome/free-solid-svg-icons @fortawesome/vue-fontawesome @mdi/font
for windows user:
npm i @fortawesome/fontawesome-svg-core @fortawesome/free-solid-svg-icons @fortawesome/vue-fontawesome @mdi/font
now you can implement the icons from fontawesome!