@Carmen,
The json in the fiddle that you have shared has label and y-value, where as while parsing the json you are trying to read x-value and y-vlaue out of it. Replacing x-value with label while parsing should work fine in your case.
chart.options.data[0].dataPoints.push({label: dps[i].label, y: dps[i].y});
Please take a look at the updated jsfiddle.
—
Vishwas R
Team CanvasJS