Vue.js: How do you implement custom event emitters?

1<!-- Child -->
2<script setup>
3const emit = defineEmits<{
4  update: [value: string]
5  submit: [data: FormData]
6}>()
7
8const handleInput = (e) => {
9  emit("update", e.target.value)
10}
11</script>

1<Child @update="handleUpdate" @submit="handleSubmit" />