The firmware files are different from each type of cameras. You have to prepare firmware files(.rui) that is suitable for the camera.

1) From DirectIP NVR

In Setup > Camera > Upgrade >, you can upgrade cameras directly from NVR. Firmware files should be stored in USB memory stick which has been put into the NVR.

2) From IDIS Discovery

To upgrade the camera from IDIS Discovery, both PC and Camera must be in the same subnet. Verify IP address first before trying to upgrade. The menu for upgrade can be found from the Management in top menu bar.