Header filled icon on product add

swym-custom.liquid

<script defer>
  function renderWishlistHeader(swat) {
    var spanElement = document.querySelector(".swym-hidden-counter");
    var headerElements = document.querySelectorAll(".swym-wishlist");
    if(swat && swat.renderWishlistCount){
      swat.renderWishlistCount(spanElement, function(cnt, elem){
        headerElements.forEach(function(hElement){
          if(cnt == 0){
            if(hElement.classList.contains("swym-added-header")){
              hElement.classList.remove("swym-added-header");
            }
          }else{
            if (!hElement.classList.contains("swym-added-header")) {
              hElement.classList.add("swym-added-header");
            }
          }
        })
      });
    }
  }

  if(!window.SwymCallbacks){
    window.SwymCallbacks = [];
  }

  window.SwymCallbacks.push(renderWishlistHeader);

</script>
<style>
   a.swym-wishlist.swym-added-header i.icon.icon-swym-wishlist:after {
    content: "\f004" !important;
  } 

  /* hide the counter */
  .swym-hidden-counter {
    display: none;
  }

</style>

Add this style to show wishlist header heart icon even when wishlist is empty count
i.icon.icon-swym-wishlist:after { content: "" !important; }