data_process.php

<?php
if(strcasecmp($_SERVER['REQUEST_METHOD'], 'POST') != 0){
    header($_SERVER["SERVER_PROTOCOL"]." 405 Method Not Allowed", true, 405);
    exit;
}

$postData = trim(file_get_contents('php://input'));
libxml_use_internal_errors(true);
$xml = simplexml_load_string($postData); 

if($xml === false) {
    header($_SERVER["SERVER_PROTOCOL"]." 400 Bad Request", true, 400);
    foreach(libxml_get_errors() as $xmlError) {
        echo $xmlError->message . "\n";
    }
    exit;
}

// echo '<pre>';
// print_r($xml); 
// echo '<pre>';

$XML = "<?xml version='1.0' encoding='UTF-8'?>
<information>
    <RequestUUID>".$xml->Header->RequestHeader->MessageKey->RequestUUID."</RequestUUID>
    <ServiceRequestId>".$xml->Header->RequestHeader->MessageKey->ServiceRequestId."</ServiceRequestId>
    <ServiceRequestVersion>".$xml->Header->RequestHeader->MessageKey->ServiceRequestVersion."</ServiceRequestVersion>
    <ChannelId>".$xml->Header->RequestHeader->MessageKey->ChannelId."</ChannelId>
</information>
";
header('Content-Type: application/xml; charset=utf-8');
echo ($XML);


// echo 'RequestUUID: ' . $xml->Header->RequestHeader->MessageKey->RequestUUID . '<br />';
// echo 'ServiceRequestId: ' . $xml->Header->RequestHeader->MessageKey->ServiceRequestId . '<br />';
// echo 'ServiceRequestVersion: ' . $xml->Header->RequestHeader->MessageKey->ServiceRequestVersion . '<br />';
// echo 'ChannelId: ' . $xml->Header->RequestHeader->MessageKey->ChannelId . '<br />';

// Source -
// https://thisinterestsme.com/receiving-xml-via-post-php/