CURL vBulletin Login and get POST - PHP

curl-vbulletin-login.php

<?php
/**
 * @author Savaş Can ALTUN <[email protected]>
 * www.savascanaltun.com.tr
 * CURL vBulletin Login Example
 * */
function vBulletinLogin($username,$password,$url,$posturl){
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_HEADER,false);
        curl_setopt($ch, CURLOPT_COOKIEFILE, 'veri.txt'); 
        curl_setopt($ch, CURLOPT_COOKIEJAR, 'veri.txt'); 
        curl_setopt($ch, CURLOPT_RETURNTRANSFER,true);
        curl_setopt($ch, CURLOPT_COOKIESESSION,true);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER,false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST,false);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION,true);
        curl_setopt($ch, CURLOPT_USERAGENT,$_SERVER['HTTP_USER_AGENT']);
        curl_setopt($ch, CURLOPT_REFERER, $url.'index.php');
        curl_setopt($ch, CURLOPT_URL, $url.'login.php?do=login'); 
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, "vb_login_username=$username&vb_login_password&s=&securitytoken=guest&do=login&vb_login_md5password=".md5($password)."&vb_login_md5password_utf=".md5($password));
        $exec = curl_exec($ch);
 
        curl_setopt($ch, CURLOPT_POST, 0);
        curl_setopt($ch, CURLOPT_REFERER, $url.'login.php?do=login'); 
        curl_setopt($ch, CURLOPT_URL, $url.'clientscript/vbulletin_global.js?v=373'); 
        $exec = curl_exec($ch);
 
        curl_setopt($ch, CURLOPT_REFERER, $url.'login.php?do=login');
        curl_setopt($ch, CURLOPT_URL, $url.'index.php'); 
        $exec = curl_exec($ch);
 
        curl_setopt($ch, CURLOPT_REFERER, $url.'index.php');
        curl_setopt($ch, CURLOPT_URL, $posturl); 

        $exec = curl_exec($ch);
        return $exec;
 
    }
 
    echo vBulletinLogin('USERNAME','PASSWORD','SİTE URL ','POST URL');
?>

what does $posturl represent ?

Go to page after logging

hi with 4.22 not work "Your submission could not be processed because a security token was missing."

can you please help me im not sure where to plugin the user, pass and url thank you