So I’m on-site where the Zmodo system is and using ZViewer on the LAN. For the individual cameras listed in ZViewer found from using LAN search and not the cameras listed under the NVR (not the cameras listed under the NVR like CH1,CH2, but those listed like IPC-192.168.1.xxx), if I right-click on it and select Remote Settings, there’s a dialog brought up. In it, I select Advanced Settings > Update. But this only provides a manual update option where you need to provide the firmware file. In the same dialog, Advanced Settings > Device Information shows the firmware version on the camera (e.g. V126.96.36.199).
I don’t recall seeing firmware made available for the cameras themselves on zmodo’s web site, but I guess they must have before if you were able to download it. I know they used to make NVR firmware available on the site, but looks like they no longer anymore and the NVR firmware can only be upgraded thru a mobile app. I recall when I was able to update the firmware of one of the cameras thru the IE Active X plugin, I didn’t have to provide any firmware file as it was able to update the firmware to the latest version at that time (188.8.131.52). But I wasn’t happy about losing the date/time stamp for that camera in the 4 channel view after the update so I didn’t do it for the rest of the cameras.