SamCheets

/applications/core/modules/front/system/login.php
don’t forget to call init.php into your external php(talking about require once)
 
also, add permission check using member class. otherwise, if your users can access while you’re working on it, something maybe can go wrong

$users_in = (\IPS\Db::i()->select('*', 'nexus_invoices', 'i_member',$member_id )); foreach ($users_in as $user_in) { //example usage of it //echo $user_in['ps_id'] } also, using first-> without checking it will give internal server error. If you only want to get first query the way you should use is:
$user_in = (\IPS\Db::i()->select('*', 'nexus_invoices', 'i_member',$member_id )); if (count($user_in) > 0) { $user_in = $user_in->first(); }  
Also, forgot to mention, you should put your where statement in array.
array('i_member=?', $member_id')  

Why you’re trying to bypass a security check lol
https://portswigger.net/web-security/csrf
 
Anyway, add this under class
public static $csrfProtected = TRUE;
 
Also, the reason why you’re getting this error due ips 4.5.x’s new csrf check.
So if you’re trying to add 4.4.x application, you might need to update more things besides of csrf.
https://invisioncommunity.com/developers/docs/invision-community-46/deprecated-methods-r190/