Zmodo Doorbell with NVR

I have a zmodo Greet Doorbell and a NVR WiFi System with 4 Outdoor and 4 Indoor Cameras.
I know the NVR only supports 8 channels for recording. I have read some time ago that it was possible to remove one camera and use that channel to record from the doorbell. I have configured that, and it works fine in my cellphone, but if I check the monitor that I have attached to the NVR, nothing shows up.
My questions (if anyone can help me) are:
1- Is it possible to have 9 cameras showing on the NVR? (with only 8 recording)
2- Is it possible for the doorbell to show image in the NVR itself and not the app?

Thanks in advance

The NVR that you currently have has only 8 channels for recording video. And believe that the Doorbell is not compatible with the NVR from what I remember from another thread.

Is it possible to show video for 9 cameras and record only 8?

PS: I was able to make it record, and to show image on the APP for the doorbell. Not on the monitor yet.

You can load as many cams or devices on the app. If you have the cloud service I believe you can record the doorbell video or have 36 hour notifications with no cloud service. Im not sure as I dont have a doorbell. But you cant show 9 video streams on the NVR.