We recommend using the async version of the API, as it'll make your website way faster. The synchronous version should only be used if it's being dynamically inserted into your website after the page's initial load (eg. A custom JS script)
<iframe height="265" style="width: 100%;" scrolling="no" title="Sync crate" src="https://codepen.io/advaith1/embed/OrxQLv?height=265&theme-id=dark&default-tab=html,result" frameborder="no" allowtransparency="true" allowfullscreen="true" loading="lazy"> See the Pen Sync crate by Advaith (@advaith1) on CodePen. </iframe>