It looks like someone has answered your post in another forum.

?php

$ldap_host = 'xx.xxx.xx.xxx'; // IP of your LDAP server
$ldap_port = 389;
$ldap_user = 'username'; // user to bind to server
$ldap_pass = '******'; // password
$ldap_context = 'ou=users,dc=example, dc=org'; // where the infos are
// https://stackoverflow.com/questions/36640272/read-deleted-users-from-active-directory
$filter = '(&(objectClass=user)(isDeleted=TRUE))';
$ldap = ldap_connect($ldap_host, $ldap_port);
if (!$ldap) {
        die("\nERROR: no connection\n");
} else {
        echo "connect OK!\n";
}
// https://stackoverflow.com/questions/6222641/how-to-php-ldap-search-to-get-user-ou-if-i-dont-know-the-ou-for-base-dn#6222836
ldap_set_option($ldap, LDAP_OPT_REFERRALS, 0); 
ldap_set_option($ldap, LDAP_OPT_PROTOCOL_VERSION, 3); 
$ldap_bind = ldap_bind($ldap, $ldap_user, $ldap_pass);
if (!$ldap_bind) {
        die("\nERROR: can not bind\n");
} else {
        echo "bind OK!\n";
}
$search = ldap_search($ldap, $ldap_context, $filter);
$info = ldap_get_entries($ldap, $search);
echo "data for " . $info["count"] . " items returned:\n\n";
for ($i=0; $i<$info["count"]; ++$i) {
        echo $i + 1, " entry:\n";
        echo "dn is: " . $info[$i]["dn"] . "\n";
        echo "\n----\n";
}
ldap_close($ldap);

It works for me on general searches, but I do not get deleted users (as your link says).

Craig