Edit in JSFiddle

$(document).ready(function() {
  $("#pdfDownloader").click(function() {

    html2canvas(document.getElementById("printDiv"), {
      onrendered: function(canvas) {

        var imgData = canvas.toDataURL('image/png');
        console.log('Report Image URL: ' + imgData);
        var doc = new jsPDF('p', 'mm', [297, 210]); 
        doc.addImage(imgData, 'PNG', 10, 10);
        doc.save('sample.pdf');
      }
    });
  });
})

<button type="button" id="pdfDownloader">Download</button>
<div id="printDiv">
  <h2>Hello World</h2>
  <p>
    this content will be printed.
  </p>
  <img src="https://picsum.photos/400/200" alt="Lorem pixum">
</div>