- strtoupper: documentation ( source)
- md5: documentation ( source)
<?php
$av_sign = 'ExSKoODNiUcAngmCQUua';
$shop_id = 6855;
$order_number = 1;
$amount = 30000;
echo strtoupper(MD5(strtoupper(MD5($av_sign) + MD5($shop_id + $order_number + $amount))));