I have tried the following in the fetch success callback, but it fails and returns false. This issue occurs in Edge browser.

document.execCommand('copy')

HTML Code:

<div id="toCopy">
    new value 12345
    <br /><br />
    <a href="#">Link</a>
</div>

Backbone JS code:

toCopy = Backbone.Model.extend({});
toCopy.fetch({
  "id": "xxx",
}).done(function(resp) {

  if (window.getSelection) {
    var range = document.createRange();
    range.selectNodeContents(document.getElementById("toCopy"));
    window.getSelection().removeAllRanges();
    window.getSelection().addRange(range);
  }
  document.execCommand("copy");
});