Hello , i saw the examples of export which calls a different php file for exporting the report but i only use one file for my report. So how do i write my javascript function "exportfunction()" to export the given gauge card ?

<div class="col-md-4 offset-md-2">
    <a onclick="exportfunction()" href="javascript:void(0);" class="btn btn-primary">Download PDF</a>
    <?php
    \koolreport\amazing\GaugeCard::create(array(
        "title"=>"Revenue",
        "value"=>7500,
        "preset"=>"success",
        "baseValue"=>10000,
        "format"=>array(
            "value"=>array(
                "prefix"=>"$"
            )
        ),
    ));
    ?>
    </div>