Update to Kirby 3 Error

I get this error after updating to Kirby 3: “Call to undefined method Kirby\Cms\App::launch()”
I have no idea what this means. Can anyone point me in the right direction?

// load kirby
require(__DIR__ . DS . 'kirby' . DS . 'bootstrap.php');
// check for a custom site.php
if(file_exists(__DIR__ . DS . 'site.php')) {
  require(__DIR__ . DS . 'site.php');
} else {
  $kirby = kirby();
// render
echo $kirby->launch();

That’s the index.php for Kirby 2, not Kirby 3. So you have to replace it with the new one as explained in the Ugrade Guide.

Ah, I was looking at the wrong update information. My bad. Thanks!