Get your own Vue server
App.vue
ChildComp.vue
main.js
 
<template>
  <div>
    <h3>ChildComp.vue</h3>
    <p>Message from parent component:</p>
    <p id="pEl">{{ message }}</p>
  </div>
</template>

<script>
export default {
  expose: ['message'],
  data() {
    return {
      message: ' '
    }
  },
  methods: {
    createMessage(msg) {
      this.message += msg + ' '
    }
  }
}
</script>

<style scoped>
div {
  border: solid black 1px;
  padding: 10px;
  max-width: 350px;
  margin-top: 20px;
}
#pEl {
  background-color: lightgreen;
  font-family: 'Courier New', Courier, monospace;
}
</style>                  
http://localhost:5173/