Nuki 3 pro & Doorbird

Hello,
I use Nuki 3.0 pro for my main door. Furthermore Doorbird is in place.
I was managing it to open the Nuki via doorbird App and doorbird indoor station.
Target is to open the Nuki via the Doorbird keypad from the outdoor station. Based on my research so far, the only way is to use API commands. Therefore the NUKI bringe is necessary. Is this the truth or any way to achieve the target by using the existing hardware?
Thanks