How do I disable right click (contentmenu ) to download image in JavaScript?

The context menu to save the image still does not appear if the user chooses to suppress alert messages from the webpage.

Works with "ALL" web browsers (including Internet Explorer 8 and above, Opera, Google Chrome, Apple Safari, and Mozilla Firefox).

  document.addEventListener("contextmenu", function(e){
    if (e.target.nodeName === "IMG") {
        e.preventDefault();
    }
}, false);
  
 window.ondragstart = function() { return false; }