How to access contract references in lumen?

Question

I'm new to Laravel and Lumen. But I have a laravel app to convert in to lumen. This is my index.php in laravel

$app = require_once DIR.'/../bootstrap/app.php'; 
$kernel = $app->make(Illuminate\Contracts\Http\Kernel::class);    
$response = $kernel->handle( $request = Illuminate\Http\Request::capture() );    
$response->send();    
$kernel->terminate($request, $response);

how can i convert this part to lumen? Could you please help me to solve this problem?