Welcome to Wefugees and thank you for your question!
We have had a few similar questions on our platform already, so I am going to link the threads here for you:
I voluntarily returned to Afghanistan, but I want to return to Europe with a visa
Is it possible to obtain a visa for Germany after voluntarily returning home?
As you will read on the threads, it should be possible to return to Germany on a Schengen visa since you returned voluntarily and therefore didn't receive an entry ban. You will find more information in the answers of the threads I linked :-)
Please reach out to us again if you have any more questions!
All the best,