Создайте проверяемый процесс оплаты.

string baseUrl = "https://mochi.bz";
string body = @"{
  ""merchant_order_id"": ""ORDER-20260920-001"",
  ""amount"": 49.90,
  ""currency"": ""USD"",
  ""payment_method"": ""USDT_TRC20"",
  ""unique_amount_direction"": ""UP"",
  ""product_type"": ""DIGITAL_SERVICE"",
  ""description"": ""Example order"",
  ""notify_url"": ""https://merchant.example.com/mochipay/notify"",
  ""redirect_url"": ""https://merchant.example.com/payment/return""
}";

string signature;
using (var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(apiSecret)))
{
    signature = Convert.ToBase64String(
        hmac.ComputeHash(Encoding.UTF8.GetBytes(body)));
}

using (var client = new HttpClient())
using (var request = new HttpRequestMessage(
    HttpMethod.Post, baseUrl + "/api/v1/orders/create"))
{
    request.Headers.Add("X-Mochi-Key", apiKey);
    request.Headers.Add("X-Mochi-Signature", signature);
    request.Content = new StringContent(body, Encoding.UTF8, "application/json");
    HttpResponseMessage response = await client.SendAsync(request);
    string json = await response.Content.ReadAsStringAsync();
}

<?php
$baseUrl = 'https://mochi.bz';
$apiKey = 'YOUR_API_KEY';
$apiSecret = 'YOUR_API_SECRET';

$payload = [
    'merchant_order_id' => 'ORDER-20260920-001',
    'amount' => '49.90',
    'currency' => 'USD',
    'payment_method' => 'USDT_TRC20',
    'unique_amount_direction' => 'UP',
    'product_type' => 'DIGITAL_SERVICE',
    'description' => 'Example order',
    'notify_url' => 'https://merchant.example.com/mochipay/notify',
    'redirect_url' => 'https://merchant.example.com/payment/return'
];

$body = json_encode($payload, JSON_UNESCAPED_SLASHES);
$signature = base64_encode(
    hash_hmac('sha256', $body, $apiSecret, true)
);

$ch = curl_init($baseUrl . '/api/v1/orders/create');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json',
        'X-Mochi-Key: ' . $apiKey,
        'X-Mochi-Signature: ' . $signature
    ],
    CURLOPT_POSTFIELDS => $body,
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_TIMEOUT => 30
]);

$json = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
$error = curl_error($ch);
curl_close($ch);

if ($json === false) {
    throw new RuntimeException($error);
}

// Preserve decimal JSON numbers as text before decoding.
$json = preg_replace(
    '/("(?:amount|base_pay_amount|pay_amount|received_amount|exchange_rate|rate_markup_percent|unique_amount_delta)"\s*:\s*)(-?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?)(?=\s*[,}])/',
    '$1"$2"', $json
);
$result = json_decode($json, true);
if ($httpCode < 200 || $httpCode >= 300 || empty($result['success'])) {
    throw new RuntimeException('MochiPay request failed. Review before retrying creation.');
}
?>