Make sure you use the official lithium twig plugin instead of this outdated version.

First enable the plugin with

<?php
Libraries::add('li3_twig', array('bootstrap' => true));

From your controller return arrays with properties that should be accessible in the Twig template. Access your fields like this in the template later. Note that the this is an automatically added reference to the Environment and under it you can lazy load helpers like in regular lithium templates.

<h1>Hello {{ name }}</h1>
{{ this.form.create }}
{{ this.form.text('title') }}
{{ this.form.select('gender', {'m':'male','f':'female'}) }}
{{ this.form.end }}