How to set Twig files in Template Loader

Thanks! I have just installed the plugin and all template files are create with twig. But my question is how i load twig template with this function.

Here is a example code where i call the tpl::load function:

array(
	'pattern' => array('(:any)/(:any)/details/(:any)'),
	'action'  => function($i18n, $section, $details) {
		$items_section = site()->visit($section, $i18n)->children()->visible();
		$items_topic = $items_section->children()->findBy('slug', $details);

		if ( isset($items_topic) && !empty($items_topic) ){
			tpl::$data = array_merge(tpl::$data, array(
				'kirby' => kirby(),
				'site' => site(),
				'pages' => pages(),
				'page' => $items_topic
			), $items_topic->templateData());

			echo tpl::load( kirby()->roots()->templates() . DS . 'sometemplate.php');
		}
	},
	'method' => 'GET'
)

But I need to load “sometemplate.twig” in the tpl::load() function.

Maybe someone has an idea how I can realize that? Is this possible?