PAYTR-Entegrasyon Merchant-oid hatası

'merchant_oid'    => uniqid(),

 'merchant_oid' => preg_replace('/[^a-zA-Z0-9]/', '', uniqid()),

https://www.paytr.com/odeme/api/get-token

$ch=curl_init();
curl_setopt($ch, CURLOPT_URL, "https://www.paytr.com/odeme/api/get-token");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1) ;
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_vals);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, 20);
$result = @curl_exec($ch);

echo "giden<pre>";print_r( $result); echo "</pre>";die();

if(curl_errno($ch))
die("PAYTR IFRAME connection error. err:".curl_error($ch));

curl_close($ch);

$result=json_decode($result,1);

if($result['status']=='success')
$token=$result['token'];
    else
die("PAYTR IFRAME failed. reason:".$result['reason']);

$ch=curl_init();
curl_setopt($ch, CURLOPT_URL, "https://www.paytr.com/odeme/api/get-token");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1) ;
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_vals);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, 20);
$result = @curl_exec($ch);

echo "giden<pre>";print_r( $result); echo "</pre>";die();

if(curl_errno($ch))
die("PAYTR IFRAME connection error. err:".curl_error($ch));

curl_close($ch);

$result=json_decode($result,1);

if($result['status']=='success')
$token=$result['token'];
    else
die("PAYTR IFRAME failed. reason:".$result['reason']);

<?php
if (!defined('BASEPATH')) exit('No direct script access allowed');

class Payments extends EduAppGT
{
    private $runningYear = '';

    function __construct()
    {
        parent::__construct();
        $this->load->database();
        $this->load->library('session');
        $this->output->set_header('Last-Modified: ' . gmdate("D, d M Y H:i:s") . ' GMT');
        $this->output->set_header('Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0');
        $this->output->set_header('Pragma: no-cache');
        $this->output->set_header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
        $this->runningYear = $this->db->get_where('settings', array('type' => 'running_year'))->row()->description;
    }

    public function paytr($invoiceId = '')
    {
        if ($this->session->userdata('login_type') != 'student' && $this->session->userdata('login_type') != 'parent') {
            redirect(base_url(), 'refresh');
        }

        // Fatura bilgilerini al
        $invoiceDetails = $this->db->get_where('invoice', array('invoice_id' => base64_decode($invoiceId)))->row();
        if (empty($invoiceDetails) || $invoiceDetails->amount <= 0) {
            $this->session->set_flashdata('flash_message', getEduAppGTLang('invalid_payment_data'));
            redirect(base_url() . 'student/invoice/', 'refresh');
            exit;
        }

        $studentId = $invoiceDetails->student_id;
        $amount = $invoiceDetails->amount;

        // Öğrenci bilgilerini al
        $studentDetails = $this->db->get_where('student', array('student_id' => $studentId))->row();
        $email = $studentDetails->email;
        $userName = isset($studentDetails->first_name) && !empty($studentDetails->first_name) ? $studentDetails->first_name . ' ' . $studentDetails->last_name : 'Misafir Kullanıcı';
        $userAddress = isset($studentDetails->address) && !empty($studentDetails->address) ? $studentDetails->address : 'Adres Bilgisi Yok';
        $userPhone = isset($studentDetails->phone) && !empty($studentDetails->phone) ? $studentDetails->phone : 'Telefon Bilgisi Yok';

        // Kullanıcı IP adresini al
        $userIp = $_SERVER['REMOTE_ADDR'];

        // PayTR ödeme entegrasyonu
        $paymentData = array(
            'merchant_id'     => 'XXXXXX', ÖZELLİKLE KAPATTIM
            'merchant_key'    => 'XXXXXX',
            'merchant_salt'   => 'XXXXXX',
            'email'           => $email,
            'user_name'       => $userName,
            'user_address'    => $userAddress,
            'user_phone'      => $userPhone,
            'payment_amount'  => $amount * 100, // TL -> Kuruş
            'merchant_oid'    => preg_replace('/[^a-zA-Z0-9]/', '', uniqid()),
            'user_basket'     => base64_encode(json_encode(array(
                array("Fatura Ödemesi", $amount, 1)
            ))),
            'callback_url'    => base_url('payments/paytr_success'),
            'merchant_ok_url' => base_url('payments/paytr_success'),
            'merchant_fail_url' => base_url('payments/paytr_failure'),
            'currency'        => 'TL',
            'user_ip'         => $userIp,
            'no_installment'  => 0, // Taksit seçeneği açık
            'max_installment' => 12, // Maksimum taksit sayısı
            'test_mode'       => 1, // Canlı mod
        );

        // Hash oluşturma
        $hashStr = $paymentData['merchant_id'] . $paymentData['user_ip'] . $paymentData['merchant_oid'] .
            $paymentData['email'] . $paymentData['payment_amount'] . $paymentData['currency'] .
            $paymentData['user_basket'] . $paymentData['callback_url'] . $paymentData['no_installment'] .
            $paymentData['max_installment'] . $paymentData['merchant_salt'];

        $paymentData['paytr_token'] = base64_encode(hash_hmac('sha256', $hashStr, $paymentData['merchant_key'], true));

        // Verileri logla
        log_message('info', 'PayTR Gönderilen Veriler: ' . print_r($paymentData, true));

        // cURL ile API bağlantısı
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, "https://www.paytr.com/odeme/api/get-token");
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $paymentData);
        curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 20);
        $result = @curl_exec($ch);

        if (curl_errno($ch)) {
            die("PAYTR IFRAME connection error. err:" . curl_error($ch));
        }

        curl_close($ch);

        $result = json_decode($result, true);

        if ($result['status'] == 'success') {
            $token = $result['token'];
            echo "<script>window.location.href='https://www.paytr.com/odeme/iframe/' + '$token';</script>";
        } else {
            die("PAYTR IFRAME failed. reason:" . $result['reason']);
        }
    }

    public function paytr_success()
    {
        // ...
    }

    public function paytr_failure()
    {
        $this->session->set_flashdata('flash_message', getEduAppGTLang('payment_failed'));
        redirect(base_url() . 'student/invoice/', 'refresh');
    }
}