Lumen not executing on MAMP or Server

Hey, Im having a problem: I can't get Lumen to execute, when i run through MAMP or on my web-server. In Mamp, i get a "browser can't find website"-error and on the server i get a blank page with no error.

The only i can get it to work is by writing "php -S localhost:8000 -t public" in the terminal.

But how do I get it to work on my server ?