** Client Side **

stripe.createSource(card).then(function(result) {
      if (result.error) {
        formIsPending = false;
        // Inform the user if there was an error
        var errorElement = document.getElementById('card-errors');
        errorElement.textContent = result.error.message;
      } else {
        // Send the source to your server
        stripeSourceHandler(result.source);
      }
    });

** Server Side **

$cardSource = \Stripe\Source::retrieve($stripeSource);

if (in_array($cardSource->card->three_d_secure, ['required', 'recommended', 'optional'])) {
  $success = $this->_process3DSecure($cardSource);
} else {
  $success = $this->_processNormal($cardSource);
}