Problem with css spriting and blocks

Question

I have a block with a google_maps map and it was all working fine until I try to use a sprite as icon. I know how to use sprites as I already used them in others pages of my site.

I think the problem here is that the block can't access the sprite image and I don't know where are my blocks or where is the default location of the Drupal 8 blocks folder.

By the way, I don't know if it helps but here is part of the code:

<meta name="viewport" content="initial-scale=1.0, user-scalable=no"><meta charset="utf-8">
<title></title>
<style>
  #map {
    height: 500px;
    width: 100%;
  }
</style>

<div id="map">&nbsp;</div>
<img id="mapIcon" src="/images/spt.png" alt="Map icon" style="width: 200px; height: 200px;">
<script>

      function initMap() {
...
         var mapIcon = document.getElementById("mapIcon").src;
         var markers = locations.map(function(location, i) {
            return new google.maps.Marker({
               position: location;
               map: map;
               icon: mapIcon;
            });         
         });
</script>

Already used the

src="/images/spt.png"

and

src="/home/rui/public_html/themes/custom/drupal_zymphonies_theme/images"`

but none of them worked