BUT the high charts code or integration is not part of TRKD API - sorry if thats not clear.
Charts is a separate service in TRKD API. You call "GetChart" operation with the chart request data - I'd suggest just using support portal to work out what request you need to get chart image you like - it returns a url in response and you use that url to get the actual chart image. The GET of theimage url may block if the image is not ready when you submit it, also the image url will expire after some time (dependent on the period selected in the chart -- minute charts expire more quickly than daily for example)
Not sure what you mean by "failing to get the chart" -- you need to provide more details on what you have done and what the problem was.