Quitting ASAP in Germany

I just started a job as a server at a restaurant and a family emergency back home (outside of Germany) means I’m probably going to have to book a flight and fuck off for an unknown period of time. Honestly maintaining this job is the last concern I have anyways- the boss is a tool and they’re dreadfully understaffed and overwork us. My question is..can I legally even do this? I’m reading my contract and it ofc says I need to give at least two weeks notice…but what happens if I just tell them I’m leaving now? Or at the end of the week? Super stressed right now and any advice would be appreciated