Dear Dawda keita,
Welcome to the Wefugees community and thank you for your question.
In general, people holding a "Duldung" (temporary suspension of deportation) can marry in Germany. But very often the process gets difficult if it comes to the provision of the required documents (passport, certificate of no-impediment etc.).
Marrying in Germany is a quite popular and much discussed topic on this platform. Therefore, we published a blog, which gives more details on this - please follow the link.
I hope this helps and don't hesitate to get back to us with any further questions.
All the best,