How to catch php request logs?

Question

PHP

I send a request to Sberbank

function register_order($order_number, $amount, $return_url, $order_description, $order_bundle, $params = [])
    {
        $data = [
            'orderNumber' => $order_number,
            'amount' => $amount,
            'language' => 'ru',
            'currency' => '643',
            'jsonParams' => '{"phone":"[phone]"}',
            'returnUrl' => $return_url,
            'description' => $order_description,
            'orderBundle' => $order_bundle
        ];

        // Запишем доп. параметры
        if (!empty($params)) {
            foreach ($params as $param_name => $val) {
                if($val !== false) {
                    $data[$param_name] = $val;
                }
            }
        }       

        $method = 'sbercredit/register.do';
        $response = $this->gateway($method, $data);
        return $response;
    }

const TEST_URL = 'https://3dsec.sberbank.ru/';

    private function gateway($method, $data)
    {
        $data['userName'] = $this->user_name;
        $data['password'] = $this->password;
        if ($this->test_mode) {
            $url = self::TEST_URL;
        } else {
            $url = self::PROD_URL;
        }

        $curl = curl_init();
        curl_setopt_array($curl, [
            CURLOPT_URL => $url . $method,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => http_build_query($data)
        ]);
        $response = curl_exec($curl);
        $response = json_decode($response, true);
        curl_close($curl);
        return $response;
    }

How can I log the full request that is sent to Sberbank?
so that I can see if it correctly generates a request by url.

It turns out that $data takes all parameters except the login password and url, then the function
$response = $this->gateway($method, $data); already adds a connection and all this is sent to the savings bank, so how exactly to intercept everything and see what is transmitted in the aggregate?