public function requestSms($authyId, $force = false) {
    $data = array(
      'authy_id' => $authyId,
      'force'    => $force,
    );

    $result = $this->apiCall('sms', $data);

    if ($result === false) {
      $this->lastError = 'AUTHY_SERVER_ERROR';
      return false;
    }

    if (isset($result->errors)) {
      $this->lastError = 'AUTHY_SERVER_INVALID_DATA';
      return false;
    }

    return true;
  }