Refund API

<?php

    $merchant_id    = "XXXXXX";
    $merchant_key   = "YYYYYYYYYYYYYY";
    $merchant_salt  = "ZZZZZZZZZZZZZZ";

    $merchant_oid   = "XXXXXX";

    $return_amount  = "11.97";

    $reference_no  = "XXXXXX11111";

    $paytr_token=base64_encode(hash_hmac('sha256',$merchant_id.$merchant_oid.$return_amount.$merchant_salt,$merchant_key,true));

    $post_vals=array('merchant_id'=>$merchant_id,
        'merchant_oid'=>$merchant_oid,
        'return_amount'=>$return_amount,
        'paytr_token'=>$paytr_token);

    $ch=curl_init();
    curl_setopt($ch, CURLOPT_URL, "https://www.paytr.com/odeme/iade");
    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($ch, CURLOPT_TIMEOUT, 90);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 90);

    $result = @curl_exec($ch);

    if(curl_errno($ch))
    {
        echo curl_error($ch);
        curl_close($ch);
        exit;
    }

    curl_close($ch);

    $result=json_decode($result,1);

    if($result['status']=='success')
    {

    }
    else
    {
        //Örn. $result -> array('status'=>'error', "err_no"=>"006", "err_msg"=>"Toplam iade tutarı odeme tutarindan fazla olamaz")
        echo $result['err_no']." - ".$result['err_msg'];
    }

# Python 3.6+

import base64
import hmac
import hashlib
import requests
import json

merchant_id = 'XXX'
merchant_key = b'XXX'
merchant_salt = 'XXX'

merchant_oid = 'XXX'

return_amount = '11.90'

reference_no  = 'XXXXXX11111'

hash_str = merchant_id + merchant_oid + return_amount + merchant_salt
paytr_token = base64.b64encode(hmac.new(merchant_key, hash_str.encode(), hashlib.sha256).digest())

params = {
    'merchant_id': merchant_id,
    'return_amount': return_amount,
    'paytr_token': paytr_token
}

result = requests.post('https://www.paytr.com/odeme/iade', params)
res = json.loads(result.text)

if res['status'] == 'success':

   print(res)
else:

    print(res)

using Newtonsoft.Json.Linq; 
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Net;
using System.Security.Cryptography;
using System.Text;
using System.Web;
using System.Web.Script.Serialization;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class iade_ornek : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e) {

        string merchant_id      = "XXXXXX";
        string merchant_key     = "YYYYYYYYYYYYYY";
        string merchant_salt    = "ZZZZZZZZZZZZZZ";

        string merchant_oid     = "";

        string return_amount     = "11.97";

        string reference_no  = "XXXXXX11111"; 

        NameValueCollection data = new NameValueCollection();
        data["merchant_id"] = merchant_id;
        data["merchant_oid"] = merchant_oid;
        data["return_amount"] = return_amount;

        string Birlestir = string.Concat(merchant_id, merchant_oid, return_amount, merchant_salt);
        HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(merchant_key));
        byte[] b = hmac.ComputeHash(Encoding.UTF8.GetBytes(Birlestir));
        data["paytr_token"] = Convert.ToBase64String(b);

        using (WebClient client = new WebClient()) {
            client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
            byte[] result = client.UploadValues("https://www.paytr.com/odeme/iade", "POST", data);
            string ResultAuthTicket = Encoding.UTF8.GetString(result);
            dynamic json = JValue.Parse(ResultAuthTicket);

            if (json.status == "success") {

                Response.Write(json);
            }else{

                Response.Write("PAYTR payment return failes. reason:" + json.err_msg + "");
            }
        }
    }
}

var request = require('request');
var crypto = require('crypto');
var express = require('express');
var app = express();

app.use(express.json());
app.use(express.urlencoded({ extended: true }));

var merchant_id = 'XXXXXX';
var merchant_key = 'YYYYYYYYYYYYYY';
var merchant_salt = 'ZZZZZZZZZZZZZZ';

var merchant_oid = 'XXXXXX';  
var return_amount = '11.97';
var reference_no  = 'XXXXXX11111';   

var paytr_token = crypto.createHmac('sha256', merchant_key).update(merchant_id + merchant_oid + return_amount + merchant_salt).digest('base64');

app.get("/", function (req, res) {

    var options = {
        'method': 'POST',
        'url': 'https://www.paytr.com/odeme/iade',
        'headers': {
            'Content-Type': 'application/x-www-form-urlencoded'
        },
        form: {
            'merchant_id': merchant_id,
            'merchant_oid': merchant_oid,
            'return_amount': return_amount,
            'paytr_token': paytr_token,
        }
    };

    request(options, function (error, response, body) {
        if (error) throw new Error(error);
        var res_data = JSON.parse(body);

        if (res_data.status == 'success') {

            res.send(response.body);

        } else {

            console.log(response.body);
            res.end(response.body);
        }

    });

});

var port = 3200;
app.listen(port, function () {
    console.log("Server is running. Port:" + port);
});