无法与PHPBB3创建登录集成

I want to integrate a login script with PHPBB3.

I have this code written.

It works well if I comment this line.

require 'forum/includes/functions.php';

But shows no output if this line is executed.

Did you tried commenting

if (!defined('IN_PHPBB'))
{
    exit;
}

from

require 'forum/includes/functions.php';

Or write this line before your include.

define('IN_PHPBB', true);