private function setPayRequestDetails($data)
    {
        $this->post = $this->setRequestData([
            'actionType'   => 'PAY',
            'currencyCode' => $this->currency,
            'receiverList' => [
                'receiver' => $data['receivers'],
            ],
            'returnUrl'       => $data['return_url'],
            'cancelUrl'       => $data['cancel_url'],
            'requestEnvelope' => $this->setEnvelope(),
            'feesPayer'       => $data['payer'],
        ])->filter(function ($value, $key) {
            return (($key === 'feesPayer') && empty($value)) ? null : $value;
        });
    }