I don’t know wp_enqueue_script works. I tested and works fine. but you can use the wp_footer hook and you can add your custom js. check below code. code will go to the active theme functions.php file.

function add_custom_scripts(){ ?>
<script type="text/javascript">
    (function($){
        $(document).ready(function() {
            $( '#menu-item-927' ).on( 'ubermenuopen', function(){
              $('.site-content').addClass('blur');
            });
        });
    })(jQuery);
</script>
<?php }
add_action( 'wp_footer', 'add_custom_scripts', 10, 1 );