In order to use jQuery you must get the library. Here we’ll use a CDN. You can import the jQuery CDN in a custom HTML block, like this:

<script
  src="https://code.jquery.com/jquery-3.6.3.min.js"
  integrity="sha256-pvPw+upLPUjgMXY0G+8O0xUf+/Im1MZjXxxgOcBQBXU="
  crossorigin="anonymous"></script>

That’s it. Now you can use jQuery.

Just for the Hell of it, let’s try and create a button that will hide/show all <p> tags. Select the button, and give it an id. You can do this in advanced settings. Here the id is removeP.

Here is the code that should remove the <p>-elements. Add the script tag to a custom HTML block:

<script>
$('#removeP').click(function(){
   $('p').toggle(777);
})
</script>

The code above will detect a click event on the button. We gave the button the id removeP. When a click is detected a new selector will mark all <p> elements and toggle them. A toggle is a bit like a normal on/off switch on the wall. If the elements are visible they will hide away. Or vice versa. The number in the parethesis (777) is the number of microseconds that the toggle animation will last.

Now try to click the button. Does it work as intended?