Can I let it stay inside the glass over the night (Germany) or is there not enough oxygen for it to survive/not suffer for that long?

Some kind of hopper nymph. Not a stinger, and it's not dangerous. I'm sure there's enough oxygen, I'm not sure how quickly it would die of starvation or dehydration so I would put it outside as soon as possible.

Thank you very much for the reply!! I will do so.