imagetoPrint(source) {
   return "<html><head><scri" + "pt>function step1(){\n" +
             "setTimeout('step2()', 10);}\n" +
             "function step2(){window.print();window.close()}\n" +
             "</scri" + "pt></head><body onload='step1()'>\n" +
             "<div class='col col-4' style='margin: 20px 20px 20px 20px;'><img alt='Scan 
              me!' style='display: block;'  src='" + source + "' /></div></body></html>";
},

var clockImage = document.querySelector("img");
var Pagelink = "about:blank";
var pwa = window.open(Pagelink, "_new");
pwa.document.open();
pwa.document.write(this.imagetoPrint(clockImage.src));
pwa.document.close();