Javascript-based objects

Hi I just installed WordPress via bitnami and I’d like to insert a JSmol applet into a post. I’ve downloaded this extension, moved it to the plugin folder and activated the plugin (https://www.ads-software.com/plugins/jsmol2wp/) but now I haven’t the foggiest of what to do. I have heard something about inserting something like:

<script type="text/javascript" src="/jsmol2wp/JSmol.min.js">jmolInitialize("jmol");</script>

Into header.php, which I have done, but I haven’t the foggiest what to do now.