The key is public by nature — it travels in the page source. It only works on guldendorf.com: a request from anywhere else is served, but never counted.
pk_423df7c7422fed8dd16ead43
<script src="https://relay.mib.news/w.js" data-key="pk_423df7c7422fed8dd16ead43" data-count="4" async></script>