V5 docker-compose + reverse proxy give blank pages

I just followed: Install Invoice Ninja v5.5 on Ubuntu 22.04

i also find it weird that there is no install command for like generating a key for the app.
Like php artisan key:generate

When i goto http://<internal_ip>/setup it downloads a setup file.
So i looks like the php is not executed.

In none of the guides i find a part where the database gets installed, so im totally confused. Its not a easy product to install…