🇮🇳India @raj.solanki

Patch No. 17 resolved this issue for me. It should fix it for you as well.
https://www.drupal.org/project/skeletontheme/issues/3275683#comment-1565... 🐛 User error: "0" is an invalid render array key in Drupal\Core\Render\Element::children() (line 98 of core/lib/Drupal/Core/Render/Element.php) with Drupal 9.3.9 Needs review

You can add the custom JavaScript for the page as a library where you're encountering the issue. Simply include the script suggested by nguyenphan → inside that custom JavaScript file—no need to make any modifications to the script.