Hi Florian, and welcome to the OH community!
It’s tricky to answer questions without having enough background information, as every OH installation is a bit different and we don’t know anything about yours. Can you review this post with tips for asking questions?
It’s possible that the answer is already in another thread, so people here like to see that someone has done a search first. If you can’t find your answers via search, then following the steps above can save a lot of time as we work together on solving your problem.
As the post above notes, we’re here to help, but we’re all volunteering our time. Hopefully we’ll get you sorted out so that you can contribute as well.
Cheers!