In vue.js 2.x I used to simply do

new Vue({
    delimiters: ['${', '}'],
    ...
}

But now it does not seem to work anymore in vue 3.0.2 or 3.1.2 :

 const app = Vue.createApp({
 delimiters: ['${', '}'],
     data() {
         return {
 
             display: 'redbox',
 
         }
     },

Follinwg the docs, I also tried adding it after constructor like:

 const app = Vue.createApp({...});
 app.compilerOptions.delimiters = ['${', '}'];
 app.mount("#vue-enhanced-page");

But it did not work either and the delimiters are shown literally like ${p.title}. So appreciate your help to fix this.

It may worths noting that I import vue from cdn to my html page:

<script src="https://unpkg.com/vue@3.1.2"></script>