Kirby 2: Serving a page on its own domain

Hello guys,
I found this beautiful Quick Tipp: Serving a page on its own domain. I also found the pendant Topic for Kirby 2 but I am not sure if the answer points to what I am looking for. So could anybody tell me, if there is a proper way to achieve what is done in the QuickTip for Kirby 3 with Kirby 2?

My Subpage on

should be rendered when i call

is it possible to use the
echo $kirby->launch();

like the
echo (new Kirby)->render();

and/or how would i do that?
Thanks a lot.