Init

curl https://sandbox3.payture.com/apim/Init \
  -X POST \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d Key=Merchant \
  --data-urlencode "Data=SessionType=Pay;OrderId=5f63838d-fb03-00c6-c890-c67cfc1c54ea;Amount=12480;Product=Ticket;Total=124.8;Phone=79156783333;Description=MyTestTransaction;Url=https://payture.com/result?orderid={orderid}&result={success};AdditionalField1=Value1;AdditionalField2=Value2"

<?php
$initData = http_build_query([
    'SessionType'      => 'Pay',
    'OrderId'          => '5f63838d-fb03-00c6-c890-c67cfc1c54ea',
    'Amount'           => '12480',
    'Product'          => 'Ticket',
    'Total'            => '124.8',
    'Phone'            => '79156783333',
    'Description'      => 'MyTestTransaction',
    'Url'              => 'https://payture.com/result?orderid={orderid}&result={success}',
    'AdditionalField1' => 'Value1',
    'AdditionalField2' => 'Value2',
], '', ';');

$data = http_build_query([
    'Key'  => 'Merchant',
    'Data' => $initData,
]);

$ch = curl_init('https://sandbox3.payture.com/apim/Init');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);

echo $response;

const initData = new URLSearchParams({
  SessionType: 'Pay',
  OrderId: '5f63838d-fb03-00c6-c890-c67cfc1c54ea',
  Amount: '12480',
  Product: 'Ticket',
  Total: '124.8',
  Phone: '79156783333',
  Description: 'MyTestTransaction',
  Url: 'https://payture.com/result?orderid={orderid}&result={success}',
  AdditionalField1: 'Value1',
  AdditionalField2: 'Value2',
}).toString().replace(/&/g, ';');

const body = new URLSearchParams({
  Key: 'Merchant',
  Data: initData,
});

const res = await fetch('https://sandbox3.payture.com/apim/Init', {
  method: 'POST',
  headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
  body,
});

console.log(await res.text());

import requests
from urllib.parse import urlencode

init_data = urlencode({
    'SessionType': 'Pay',
    'OrderId': '5f63838d-fb03-00c6-c890-c67cfc1c54ea',
    'Amount': '12480',
    'Product': 'Ticket',
    'Total': '124.8',
    'Phone': '79156783333',
    'Description': 'MyTestTransaction',
    'Url': 'https://payture.com/result?orderid={orderid}&result={success}',
    'AdditionalField1': 'Value1',
    'AdditionalField2': 'Value2',
}).replace('&', ';')

response = requests.post(
    'https://sandbox3.payture.com/apim/Init',
    data={
        'Key': 'Merchant',
        'Data': init_data,
    },
)

print(response.text)

using System.Net.Http;
using System.Collections.Generic;
using System.Threading.Tasks;

var initData = string.Join(";", new[]
{
    "SessionType=Pay",
    "OrderId=5f63838d-fb03-00c6-c890-c67cfc1c54ea",
    "Amount=12480",
    "Product=Ticket",
    "Total=124.8",
    "Phone=79156783333",
    "Description=MyTestTransaction",
    "Url=https://payture.com/result?orderid={orderid}&result={success}",
    "AdditionalField1=Value1",
    "AdditionalField2=Value2",
});

var form = new Dictionary<string, string>
{
    ["Key"]  = "Merchant",
    ["Data"] = initData,
};

using var client = new HttpClient();
var response = await client.PostAsync(
    "https://sandbox3.payture.com/apim/Init",
    new FormUrlEncodedContent(form));

Console.WriteLine(await response.Content.ReadAsStringAsync());