How to prefill the description field in the webWidget (classic) inside a custom function

I tried to follow the docs but I did not find a solution for prefilling the description or any custom fields in the webWidget form.

I need to fill the webWidget form a JS function

<script type="text/javascript">
  zESettings = {
    webWidget: {
      contactForm: {
          title:{ '*': 'title'},
          launcher:{'en-US': 'button label'},
          attachments: false,
      }
    }
  };

  zE('webWidget', 'hide');

function setWidget(name,email,description){
 
zE('webWidget','show');
zE('webWidget','open');
zE('webWidget','prefill', {
    name: {value: name},
    email: {value: email},
    description: {value: description}
});
}

</script> 

In this code launcher does not work and the prefill description does not work. I tried to move zESettings inside the function but that did not work. I tried add the zE('webWidget', 'identify') block and that did nothing. So I do not have anything else to try please help.

zESettings works for prefiling data only on page load. Is there any other function that could be used to prefill the the description?