Been trying to get a listing of all of a given data point via the swagger API: /v1/point-values/{xid}/latest

Given there are several hundred entries that I need a response for I am trying to script the process but keep running into the issue of "failed to open stream: HTTP request failed! HTTP/1.1 403 Access Denied" even though a copy & paste of the string into a browser works perfectly.

The script in question is very simple:

<?php
$dpval = 2; //up to 321
$dpnum = str_pad($dpval, 16, "0", STR_PAD_LEFT);
$dpstring = "DP_HGU1_2_UII_$dpnum";
$url = "http://<ip.address>:8080/rest/v1/point-values/$dpstring/latest?useRendered=true&unitConversion=false&limit=100&useCache=true";

while ($dpval <= 321) {
echo $dpstring;
echo "<br>";
echo file_get_contents($url);
echo "<br>";
echo "<br>";
$dpval++;
}
?>

Have also tried numerous variations with various permutations with fopen and stream_context_create.

Cheers,

David