Welcome to our community and thank you for your question!
You are an asylum seeker. That's why you have a document called "Aufenthaltsgestattung". It allows you to stay in Germany for the duration of your asylum procedure. Unfortunately it's not possible for you to travel abroad with this document. If you want to marry in Poland you would have to wait to be granted asylum and to get a blue passport that enables you to travel.
But it's possible for your fiancé to come to Germany to marry here. You are allowed to get married no matter what your legal status is. You will find extensive information about this topic on the Wefugees platform. For example here: