Dear @Ronns,
Welcome back to the Wefugees Community and thank you for reaching out to us for your friend.
Unfortunately, while holding a so-called “Duldung” (temporary suspension of the deportation), a person will not be eligible for permanent residence permit or qualify to get the German citizenship.
Whether your friend might be able to obtain a temporary residence permit depends on his individual conditions (his work situation etc).
Did you already learn about the new law in preparation (which is neither finally drafted nor implemented yet) - the so-called “Chancen-Aufenthaltsrecht”. Please follow the link for more information on this.
Hopefully this law will introduced soon and maybe it’s also a perspective for your friend.
I hope this helps and please don’t hesitate to get back to us with any further questions.