I'm using PHP with Swup to refresh pages without refresh the whole site. I'm using JavaScript function on every page (inside the body tag for exa) with functions that using ajax reguests every x seconds. code example:

<script defer>
    $(document).ready(function () {
    $.ajax({....});
// along with some more functions for handling the ajax request.
</script>

I got a main js file that handles the const swup = new Swup(); code. my question is, how i can handle it, so it will load the js tag on the body of each page, and when i change the page, it will unload the previous requests/js (if needed?) and wont refresh the global js (it doesnt atm)

until now i tried to make the <script> tag without the defer option, and put it inside the main tag of every page and put there the page function like that:

const init = function() {
      $.ajax({ ... });
}

and

swup.on('contentReplaced', init);

on the main script (from the header) so it will call the function. but for some reason its calling the function from the page that loaded first time, and if i move to another page, its still calling the same function from the first page.. how i can fix that?

edit: maybe its not reloading the <script> tag from the body? how i can change that? - can send the url of the website if anyone can help..