Vue.js: How do you use Composition API with options API?

1<script>
2export default {
3  data() { return { count: 0 } },
4  computed: { doubled() { return this.count * 2 } },
5  methods: { increment() { this.count++ } }
6}
7</script>

1<script setup>
2import { ref, computed } from "vue"
3
4const count = ref(0)
5const doubled = computed(() => count.value * 2)
6const increment = () => count.value++
7</script>