Using Font Awesome in Vue 3

These steps got it working for me:

1. Install latest-3 (3.0.1) of vue-fontawesome, which is compatible with Vue 3, and the icon dependencies:

   npm i --save @fortawesome/vue-fontawesome@latest-3
   npm i --save @fortawesome/fontawesome-svg-core
   npm i --save @fortawesome/free-solid-svg-icons
   

2. In main.js, select the icons from @fortawesome/free-solid-svg-icons to load:

   import { library } from "@fortawesome/fontawesome-svg-core";
   import { faPhone } from "@fortawesome/free-solid-svg-icons";
   
   library.add(faPhone);
   

3. Globally register the font-awesome-icon component:

   import { FontAwesomeIcon } from "@fortawesome/vue-fontawesome";
   
   createApp(App)
     .component("font-awesome-icon", FontAwesomeIcon)
     .mount("#app");
   

4. In src/App.vue, use the component like this (note the icon name is phone, not faPhone):

   <!-- explicit style -->
   <font-awesome-icon :icon="['fas', 'phone']" />
   
   <!-- implicit style (fas is assumed) -->
   <font-awesome-icon icon="phone" />
   

demo