Include remoted Library (API 4.5 Mapy.cz) to Google Chrome Extension

I am confused. I'am trying to make little chrome extension (popup) and I need connect to remoted API. This is, what I would use, if it is a standard web page:

<script type="text/javascript" src="http://api4.mapy.cz/loader.js"></script>
<script type="text/javascript">Loader.load();</script>

I experimented with including new element script to head (not works for me). But I couldn't believe, there is no开发者_如何学JAVA easier way...

Please, show me the best way.

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EDIT:

Linking the API loader is fine and works. Thanks to @serg. So, my code of popup looks like this:

<script type="text/javascript" src="http://api4.mapy.cz/loader.js"></script>
<script type="text/javascript">
    Loader.load();
    var center = SMap.Coords.fromWGS84(16.61574, 49.20315);
</script>

Object Loader is defined and it is OK. Loader should load the whole API either object SMap. But SMap is undefined. What next?

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If you need to make ajax requests to this remote API, you need to list API domain in the permissions in your manifest:

{
  "permissions": [
    "http://api4.mapy.cz/"
  ],
}

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Finally I ask developer from Mapy.cz and they gave the solution. Instead of using Loader.load() which cause including additional script and async load - use this way:

Loader.async = true;
Loader.load(null, null, function(){
    alert(123); // it works...
    // custom code calling objects etc. from API
    // ...
});

Final Example of usage