<div id="app">
  <form @submit.prevent="onSubmit">
    <input v-model="email" placeholder="Email" />
    <button type="submit">Subscribe</button>
  </form>
  <p v-if="submitted">Thanks, {{ email }}!</p>
</div>

<script>
const app = Vue.createApp({
  data() {
    return { email: '', submitted: false }
  },
  methods: {
    onSubmit() {
      this.submitted = true
    }
  }
})
app.mount('#app')
</script>