UniFi: Adopt 3rd Party ONVIF Devices via IP Address

Issue
UniFi NVR's will only detect 3rd party devices that are on the same network. If you have cameras on a different network/vlan, you will need to follow this guide to connect them to the UniFi NVR.

Solution

Login to the UniFi NVR console and go to the UniFi Devices dashboard.
Click the ? icon in the top right corner
Click the "try advanced adoption" link at the bottom of the help modal.
Enter the IP Address and ONVIF credentials for the camera. Click Confirm to adopt the camera.
The camera should now show in the UniFi Devices dashboard. Edit the device and set it's name and add any tags to the device that are needed.