Error using CDN and external JS file

[PerryCodes]

Trying to use this with CDN and getting an error: [Vue warn]: A plugin must either be a function or an object with an "install" function.

index.html snippet:

<script src="https://unpkg.com/vue3-lazyload"></script>
<script src='https://website.com/content/app.js'></script>
...
<div id="app"></div>

app.js snippet:

const app = Vue.createApp({
   ...
});
app.use(VueLazyload);
app.mount('#app');