JSFiddle - React, Tailwind, and code Playground

HTML

<a href="/shop/product?ie=UTF8&amp;asin=Z00FDLN878&amp;tab=UK_Default" 
target="_blank">
    <img width="125" height="125" border="0" src="http://ecx.images-amazon.com/images/I/01W9a7gwosL.jpg" alt="43453">
    </a>
    
    <hr/>
<a href="#asin=sdfwe">
    <span>something that isn't an image</span>
</a>
    <br/>
    <hr/>
<a href="#asin=sdsdsfwfe">
    text
</a>

JavaScript

// the new base url
var base = ' https://www.example.co.uk/gp/wine/order?ie=UTF8&asin=';
var links  = document.getElementsByTagName('a');

for(var i = 0;i < links.length;i++){
    var linkElement = links[i];
    var firstChild = linkElement.children[0];
    if (typeof(firstChild) !== "undefined" && firstChild.tagName=="IMG") { 
    // check each link for the 'asin' value
    var result = /asin=([\d\w]+)/.exec(links[i].getAttribute('href'));
    if(result){
        // make a new url using the 'base' and the 'asin' value
        links[i].setAttribute('href', base+result[1]);
    }}
}