Custom - Link Add - All Pages DOM

<script>
(function () {
    var links = document.querySelectorAll('a[href*="amazon.com"]') //change amazon.com to any domain you want to target
    var attachmentString = "" //the string to be attached to the end of the link

    links.forEach(function(link){
     var original = link.getAttribute("href");
     link.setAttribute("href",original+attachmentString)
	})
})();

</script>

thank you for this.