JavaScript not working on Divi

Hello dear community,

I'm trying to set up a new website for my school, and I'd like to use JavaScript for it. But even though I watched some tutorials (e.g. https://divilover.com/add-javascript-jquery-code-divi-theme/), even simple code I put in Theme options -> Integration -> Add code to head (or body), it doesn't work.
Is there a catch, do I need certain modules or plugins for JavaScript code to work?

Thanks!

 

Yeah, I know it should, but it doesn't when I put the code either to head or body, nothing else is shown but the code itself (attached screenshot) for instance, this piece of code:
<script>
jQuery(function($){
alert('Hi! This is working!');
});
</script>
is shown only as plain text, nothing else happens. Tried it in all browsers (Chrome, Explorer...), but nothing changes. I also can't upload js files, since our national website organisation doesn't offer that possibility, I can only edit code from within Divi... what am I missing?? Are there specific tags I'm missing?

If I try to insert the code (for instance the above one) onto a page inside Divi, it shows also only the code as text... It's depressive, but I have no idea why it won't work...
Any ideas?? Thanks in advance...