I am trying to create a PHP script which will be run via a Linux (Debian) CLI using PHP 7.4. This script is trying to add a user in Active Directory to a group and that part work.

<?php

$ldaphost = 'ldaps://domain.uk';
$ldapport = 636;

putenv('LDAPTLS_REQCERT=never');

$ds = ldap_connect($ldaphost, $ldapport) or die("Could not connect to $ldaphost");
    ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
    ldap_set_option($ds, LDAP_OPT_REFERRALS, 0);

if ($ds) {
    
    $username = "cn=user1,ou=test,dc=domain,dc=uk";
    $upasswd = "XXXXXXX";

    $ldapbind = ldap_bind($ds, $username, $upasswd);

        $groupDN = 'cn=temp-access,ou=test,dc=domain,dc=uk';
    $userDN = 'cn=user1,ou=test,dc=domain,dc=uk';

     $entry = ['member' => $userDN];
     ldap_modify($ds, $groupDN, $entry);

}

What I actually need the script to do is also set the TTL on the groupDN to support temporary group membership. However, when setting the $groupDN variable to the following string I get an error.

$groupDN = '<ttl=1866,cn=temp-access,ou=test,dc=domain,dc=uk>';

PHP Warning: ldap_modify(): Modify: Invalid DN syntax

According to the following post it is possible to achieve in Python.
Add User To an Active Directory Group temporarily in Python

Any advice would be greatly appreciated.