If you serve the jsnlog.js file from your own web server, then the distance between your server and your user delays loading of the file. For example, your web server is in the US and your visitor is in Europe.
To solve this, you can host jsnlog.js and other static files on a Content Distribution Network (CDN). This automatically places your files on servers around the world. This way, your files are served from whatever server is closest to your user.
To load jsnlog.js from this CDN, use this script tag:
<script crossorigin="anonymous" src="https://cdnjs.cloudflare.com/ajax/libs/jsnlog/2.28.0/jsnlog.min.js"></script>