chartjs mixed type display want to set value on top of each bar

by lemon kazi

HTML

<!DOCTYPE html>
  <html>

    <head>
      <meta charset="utf-8" />
      <title></title>
      <script src="https://www.chartjs.org/dist/master/Chart.min.js"></script>
      <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.bundle.js"></script>
      <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>



    </head>

    <body>
      <canvas id="canvas" style="display: none;"></canvas>
<div id="createPNGButton"  style="display: none;">
    <button>Save as Image</button>        
</div>
<input type="hidden" name="input_camera_passport" id="input_camera_passport" />
<!-- <a href="#" id="downloader" onclick="download()" download="image.png">Download!</a> -->
<img id="url" />
      <script>
			
			
		
			$imageContent = file_get_contents($img_base64_encoded);
			$path = tempnam(sys_get_temp_dir(), 'prefix');
			
			file_put_contents ($path, $imageContent);
			
			$htmlContent = '<img src="' . $path . '">'; 




			// Convert canvas to image
document.getElementById('createPNGButton').addEventListener("click", function(e) {
    var canvas = document.getElementById('canvas');

    var dataURL = canvas.toDataURL("image/png", 1.0);

$('#input_camera_passport').val(dataURL);
	document.getElementById("downloader").href = dataURL;
	
    //downloadImage(dataURL, 'my-canvas.png');
});


// Save | Download image
//function downloadImage(data, filename = 'untitled.png') {
    //var a = document.createElement('a');
    //document.getElementById("downloader").href = dataURL;
    //document.getElementById("downloader").download = filename;
    //document.body.appendChild(a);
    //a.click();
//}

        var barChartData = {
          labels: ['6/30', '7/31', '8/31'],
          datasets: [{
              type: 'line',
              label: 'line',
              borderColor: 'red',
              borderWidth: 2,
              fill: false,
              data: [73.6, 72.0, 71.0],
              yAxisID: 'y-axis-2'
           ...