How to process gzipped chunked raw post data in PHP

Question

I have tried reading php://input, $_POST, $_GET, $_REQUEST but everything returns blank or empty array.

When I test on https://webhook.site I get the following data (image below) which tells me it's working as expected but reading through PHP script returns blank for everything.

When I do a curl request to my script, php://input works just fine and outputs the data, however not from the app, but the app submits fine to webhook.site.

The only reason I can think of it not showing anything would be maybe because it is gzipped/chunked (from data in webhook.site). How do I process gzipped chunked raw post data?

So far I have tried the following to no avail;

$datas = array();
$datas[] = print_r($_POST, true);
$datas[] = print_r($_GET, true);
$datas[] = print_r($_REQUEST, true);
$datas[] = file_get_contents('php://input');

file_put_contents("logs/log.txt", print_r($datas, true));

Which outputs either blank or empty array.

Can someone please point me in the right direction?