how to use Highcharts library in the email.

Hello everyone,

I am trying to use highcharts library in the email but I m getting an empty image. Any idea?

Basically I am using a simple JS code where I m gathering all information I need create edm by code as showed below

var xmlTargeting = <delivery>
<targets >
<deliveryTarget>
<targetPart exclusion='false' ignoreDeleteStatus='false'>
<where>
<condition expr={'@id=' + 6952894}/> // Recipient ID
</where>
</targetPart>
</deliveryTarget>
</targets>
</delivery>;

/// create template

var finalDev = nms.delivery.CreateFromModel('ssgWeeklyReportProfile', xmlTargeting); // Delivery internal name ( Template )
var deliv = nms.delivery.create(finalDev);

var str= "<script src='https://code.highcharts.com/highcharts.js'></script>"
+"<script src='https://code.highcharts.com/modules/exporting.js'></script>"
+"<script src='https://code.highcharts.com/modules/export-data.js'></script>"
+"<script src='https://code.highcharts.com/modules/accessibility.js'></script>"
+"<STYLE>"
+".highcharts-figure,"
+".highcharts-data-table table {"
+"min-width: 310px;"
+"max-width: 800px;"
+"margin: 1em auto;"
+"}"

+"#container {"
+"height: 400px;"
+"}"
+".highcharts-data-table table {"
+"font-family: Verdana, sans-serif;"
+"border-collapse: collapse;"
+"border: 1px solid #ebebeb;"
+"margin: 10px auto;"
+"text-align: center;"
+"width: 100%;"
+"max-width: 500px;"
+"}"

+".highcharts-data-table caption {"
+"padding: 1em 0;"
+"font-size: 1.2em;"
+"color: #555;"
+"}"

......... 

deliv.mailParameters.subject="Monthly EDM KPI Reports"+formatDate(new Date(), "%2D/%2M/%2Y");
deliv.content.html.source=str; /// link string to html

deliv.save();
nms.delivery.PrepareFromId(deliv.id);