How to register for the Oberhausen 'Safari zone' event?

Hi all! I'm interested in the Safari Zone event in Oberhausen this September. I've read that you need tickets to join and was wondering if there was more known about this. I have several questions, such as: do I need tickets beforehand? Where can I get them? How much do they cost? Can non-Germans attend?

Can anyone provide some more clarity on the subject?