<?php
$merchantCode="D4672";
$merchantOrderId="67325076071473727094";
$paymentAmount="10000";
$merchantKey="168be7bdabdb49bc3885aec3e8c6d8bf";
$signature=$merchantCode . $merchantOrderId . $paymentAmount . $merchantKey;
$signaturemd5 = md5($signature);
echo $signaturemd5."<br/>";
echo  round(microtime(true) * 1000);