<div id="app">
  <alert-banner message="Global registration example" />
</div>

<script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
<script>
  const app = Vue.createApp({})

  app.component('alert-banner', {
    props: ['message'],
    template: '<p class="alert">{{ message }}</p>'
  })

  app.mount('#app')
</script>