BIM/signin.php

<?php

session_start();

include 'vendor/autoload.php';

try {
    $loader = new Twig\Loader\FilesystemLoader('templates');
    $twig = new Twig\Environment($loader);
    $twig->addGlobal('session', $_SESSION);

    $template = $twig->load('signin.html.twig');

    echo $template->render();
} catch (Exception $e) {
    die ('ERROR: ' . $e->getMessage());
}