THE JAVASCRIPT LIBRARY “LOZAD.JS”

functions.php

wp_register_script('lozad', 'https://cdn.jsdelivr.net/npm/lozad', array(), '', false);

wp_enqueue_script('lozad');

в шаблоне

<script type="text/javascript">

const observer = lozad(); // lazy loads elements with default selector as ".lozad"

        observer.observe();

</script>