To finish my website I need to add a JS script which is applied to the header. I installed a plugin called "JavaScript AutoLoader", made a new directory called "jsautoload" in my child theme folder and inserted the script. I also added code in functions.php for it to load the jQuery library. Some time ago I added the script to the JS folder of my parent theme. None of these methods work. Do I need to do something else? This is my JS script:

<script
   src=".4.1.js"
   integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU="
   crossorigin="anonymous">
</script>
<script type="text/javascript">
   $(document).on('click', 'ul li', function(){
   $(this).addClass('active').siblings().removeClass('active')
   })
</script>