Hello @Sandy
Nice to hear from you again!
Since you are still in the asylum procedure you are not allowed to leave Germany. If you want to marry your fiancé has to come to Germany. It's risky to show your passport at Standesamt especially if you have already been rejected by BAMF once. If you get a negative result on your appeal you can easily get deported back to your home country if authorities hold your passport. On the other hand, it's inevitable to hand it in at Standesamt if you want to marry. So it's quite a dilemma.
Is there a way that you can go to a counselling center or other instutions/experts that can take a closer **** at your case? It's not possible for us to give detailed advice online, especially when there is a lot at stake like in your case. It's better to have someone take a **** at all the details and to decide on what's best to do.
Best regards,
Thorgen