Webviewer({
  initialDoc: ...,
  path: '/lib',
}, document.getElementById('viewer')).then(instance => {

  const { Annotations, docViewer, Actions } = instance

  const rect = new Annotations.Rect(10,10,10,10)

  const link = new Annotations.Link({ rect: rect})
  link.setWidth(200)
  link.setHeight(200)
  link.PageNumber = 1

  const destination = new Actions.GoTo.Dest({ page: 4})
  const goToAction = new Actions.GoTo({dest: destination})
  link.addAction('U', goToAction);

  const annotManager = docViewer.getAnnotationManager()
  annotManager.addAnnotation(link)

});