Can I you use addEventListener in Squarespace? Custom code

Site URL: https://www.keystorage.com/resource-center

Issue 1: I have a page I am developing where I have block areas I made with the text tool. the text area has a background image which makes it seem more like a button block. The problem I have run into is only the text is linked and not the entire background area which I did setup with a pointer. I have tried to add an eventlistener using JavaScript to make that whole area clickable and then load another page on click. Nothing I seem to do works. I was using this code here I got from w3schools: 

<script>
document.getElementById("block-yui_3_17_2_1_1665162425531_150044").addEventListener("click", loadExternalPage);

function loadExternalPage() {
  window.location.href = "https://info.keystorage.com/s/PKJLgJMExM3M9yW";
}
</script>

Issue 2: I use background images from the static and hover image states. While hovering the image changes to its hover background image but there is a flicker of blue that comes before the hover state. Im pretty sure this blue comes from the section intrinsic color theme I have chosen. Is there away to get rid of that blue flicker?