Vue 3

HTML

<script src="https://unpkg.com/vue@3.2.36/dist/vue.global.prod.js"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/kognise/water.css@latest/dist/dark.min.css">
<script src="https://unpkg.com/vue-options-api-constants-plugin@1.0.0/cdn.js"></script>
<div id="app">
  {{ AN_EXAMPLE }}
</div>

JavaScript

console.clear();

const AN_EXAMPLE = 'An example';

const app = Vue.createApp({
  constants: {
    AN_EXAMPLE
  },
  data: function () {
    return {};
  },
  methods: {}
});
app.use(window.constantsPlugin);
app.mount('#app');