Handler method "onCloseModal" not fired after closing modal

[waspper]

Hello guys...

I've been trying to perform some actions every time the modal is closed (a custom implementation with https://checkout.epayco.co/checkout.js). I've configured the handler in following way:

var handler = ePayco.checkout.configure({
  key: 'MY_KEY',
  test: true
});

Then, I've added the mentioned method in following way:

handler.onCloseModal = function () {
  console.log('Closing dialog called!');
};

And finally, by calling handler.open(params), it is opened, and process works. But when I close the modal (by clicking on the "X" icon), then the method is not called. I remember it used to work in older version, or maybe before any change in API.

Any idea about this?