Export still from Adobe Premiere Pro CC based on markers

dts-export-markers.jsx

/*
name: DTS Export Markers 
description: exports markers into JPGs and creates XML in a format DTS's video player can read
author: John Dyer
created: 2017-04-07
updated: 2017-04-11
version 1.0.1
references:
http://cssdk.s3-website-us-east-1.amazonaws.com/sdk/2.1/docs/WebHelp/references/csawlib/com/adobe/premiere/package-detail.html
https://github.com/Adobe-CEP/Samples/blob/master/PProPanel/jsx/Premiere.jsx

Change Log
2017-04-11 - 1.0.1
* Filenames now based on Sequence name rather than Project name
* Tried using a Folder dialog prompt but decided not to
* Discovered the JPG output only likes to go to /Volume/ but not other locations
*/

// get the project and markers objects
var project = app.project;

var activeSequence = project.activeSequence;
var markers = activeSequence.markers;

// find the path to the project and it's name

var projectPath = app.project.path;
projectPath = projectPath.substring(0, projectPath.lastIndexOf('/')) + '/slides/';

/*
OPTIONAL: Ask user for output directory
var userChosenPath = Folder.selectDialog("Choose output folder");
userChosenPath += "/";
*/

var outputPath = projectPath;

// create output directory if it doens't exist
var outputFolder = new Folder(outputPath);
if (!outputFolder.exists) {
    outputFolder.create();
}

// convert sequence name (CCC_UUU_VVV_otherstuff to just CCC_UUU_VVV)
var sequenceFilename = activeSequence.name;
var filenameParts = sequenceFilename.split('_');
var slideFilenamePrefix = filenameParts[0] + '_' + filenameParts[1] + '_' + filenameParts[2];

// start the XML output (DTS specific)
var xmlOutput = '<?xml version="1.0" encoding="utf-8"?>\n<slides>\n';
var xmlFilename = slideFilenamePrefix + '_slides.xml';

// spin through the markers and make XML
var numMarkers	= markers.numMarkers;
if (numMarkers > 0) {
    var marker_number = 1;
    for(var current_marker	=	markers.getFirstMarker();
            current_marker	!==	undefined; 
            current_marker =	markers.getNextMarker(current_marker)){
                
        var timecode = convertSecondsToTimecode( parseFloat( current_marker.start.seconds ), true),
            slideFilename = slideFilenamePrefix + '_s' + padLeft(marker_number.toString(), '0', 3) + '.jpg';
           
        // add to XML
        xmlOutput += '\t<cue timeCode="' + timecode + '" slideFileName="' + slideFilename + '" />\n';

        // create thumbnail
        activeSequence.setPlayerPosition(current_marker.start.ticks);
        exportThumbnail (outputPath + slideFilename);
        
        marker_number = marker_number + 1;
    }    
}

xmlOutput += '</slides>';

// SAVE output
var file = new File(outputPath + xmlFilename);
file.encoding = "UTF8";
file.open("w", "TEXT", "????");
file.write(xmlOutput);
file.close();

// DONE!!


function exportThumbnail(imageFilePath) {
    app.enableQE();

	var activeSequence	= qe.project.getActiveSequence(); 	// note: make sure a sequence is active in PPro UI

    if (activeSequence) {
        var time			= activeSequence.CTI.timecode; 	// CTI = Current Time Indicator.

        activeSequence.exportFrameJPEG(time, imageFilePath);
    } else {
        $.writeln("Active sequence required.");
    }    
}


function convertSecondsToTimecode(seconds, forceHours) {
    //seconds = Math.round(seconds);
    var hours = null,
        minutes = Math.floor(seconds / 60);
    
    if (seconds < 60) {
        minutes = 0;
    }
    
    if (minutes >= 60) {
        hours = Math.floor(minutes / 60);
        minutes = minutes % 60;
    } else {
        hours = 0;    
    }
    
    var printHours = (hours == null) ? '00' : (hours >= 10) ? hours : "0" + hours;
    var printMinutes = (minutes >= 10) ? minutes : "0" + minutes;
    var printSeconds = seconds % 60;
    printSeconds = (printSeconds >= 10) ? printSeconds.toString() : "0" + printSeconds;
     
    if (printSeconds.length > 4) {
        printSeconds = printSeconds.substring(0,4);
    }
    return ((hours > 0 || forceHours === true) ? printHours + ':' : '') + printMinutes + ':' + printSeconds;

}

function padLeft(value, charToPad, length) {
    return (value.toString().length < length) ? padLeft(charToPad+value, charToPad, length):value;
}

I found your blog blog
and tried the Extendscript toolkit...
but when I click the "run button"
the code only automated export the .xml file in "/slides",
like
"

<?xml version="1.0" encoding="utf-8"?>
<slides>
	<cue timeCode="00:00:06.2" slideFileName="让人有代入感，和自己产生关联的广告 - YouTube_undefined_undefined_s001.jpg" />
	<cue timeCode="00:00:07.4" slideFileName="让人有代入感，和自己产生关联的广告 - YouTube_undefined_undefined_s002.jpg" />
	<cue timeCode="00:00:11.6" slideFileName="让人有代入感，和自己产生关联的广告 - YouTube_undefined_undefined_s003.jpg" />
	<cue timeCode="00:00:15.5" slideFileName="让人有代入感，和自己产生关联的广告 - YouTube_undefined_undefined_s004.jpg" />
	<cue timeCode="00:00:18.8" slideFileName="让人有代入感，和自己产生关联的广告 - YouTube_undefined_undefined_s005.jpg" />
	<cue timeCode="00:00:23.0" slideFileName="让人有代入感，和自己产生关联的广告 - YouTube_undefined_undefined_s006.jpg" />
</slides>

but I can't find any image file in the /slides ...
I am using the Adobe Pr 2015