I see other threads on this. for instance,
It's been a while, but I think this is how I did it. Using composer, you can determine the IP address of the Door Station. Click on the door station and view its IP Address using the monitoring/properties tab. Its likely a DHCP auto assigned IP address. You might want to change it to a static IP address, but that isn't necessary. To do that, you would have to log into the doorstation's IP address with a browser, such as firefox (I don't believe chrome or IE lets you due to the outdated security certificate) and change its networking configuration to a static IP.
Then log into your HIK NVR, using a browser and its IP address. Under system settings/configuration/camera management, you can click on an unused camera, and modify. Change the camera's setting from Plug-n-Play to Manual, type in the door station's ip address, and select custom 1 as the protocol. if another doorstation is to be added, use custom 2 for the second, etc. type in the doorstation's login user name (root) and password (t0talc0ntr0l4!). management port should be 554 and channel 1. I think that is basically what I did.