first add this code on function.php or snippets plugin and then create new section like image below, or download json file have I made.
add_action( 'wp_head', function () { ?>
<script>
jQuery( document ).ready( function( $ ) {
$("#hidehello").click(function(){
$("#hellobar").hide();
});
});
</script>
<style>
</style>
<?php } );


