Hostinger: Can’t get window.location.search

Hostinger builder just allow us to add a html code in a iframe section.

so, I added my code and I need to get window location search.

<script>
    async function getpostID(){
        const urlParams = new URLSearchParams(window.location.search);
        console.log(urlParams);
        const postId = urlParams.get('id');
        console.log(postId);
        return postId;
        
    }
    // Example function to fetch blog post by ID
    async function fetchBlogPostById(postId) {
      }
    document.addEventListener('DOMContentLoaded', () =>  fetchBlogPostById( getpostID() ));

</script>

I tried to set the function getpostID() in the integration section of Hostinger
but the internal code of the Iframe can’t see it