How i save. Canvas in db. With background. Which comes from user uploaded in Django field img

I successfully save if static path
How pass field image of customer to java
There many trial but src for field from model i cant save both i f i add url in style background not saved your text

type h

window.onload = function(){

  //var dataImage = localStorage.getItem('imgData');



  //var canvas = document.getElementById("myCanvas");

  var context = canvas.getContext("2d");

  var imageObj = new Image();

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

  imageObj.onload = function(){

    context.globalCompositeOperation="destination-over";

    context.drawImage(imageObj,250, 50,700,400);// i edit it was  context.drawImage(imageObj,50, 50);

    context.font = "40pt Comic Sans MS";

    context.fillText("draw here",20,80);

    context.fill();

    context.globalAlpha = 0.5;



  };



  //function getBase64Image(img) {

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



      //return dataURL.replace(/^data:image/(png|jpg);base64,/, "");

  //}





  //here source imge for back ground if you want make it dynamic from upload by user  use url of media   <canvas  style="background: url('{{ user.profile.profile_pic.url }}')" <canvas  style="background: url({% static 'images/aes.png'%})"

  imageObj.src = dataURL;//"data:image/png;base64," + dataImage;//'/media/imggg/gggg.png';//"{{ img }}"//'/media/imggg/gggg.png';



  //cnanvas.innerHTML = `<img src="${url}" width="50%">`;//`media/${object.img.url}`//("<img src="{{ MEDIA_URL}}{{field.img.url}}">"); //<img src="{{ MEDIA_URL}}{{ City.image.url }}">"url '(${field.img.url})' ";//=("<img src='${{field.img.url}}'>");

  };

ere

    </main>
</body>


<script type="text/javascript">

</script>

</html>

Can pass variable from Django models and view to java
Ok any other help i needs
Edited code how make dynamic uploaded pic background drawing on it then save