The details of the page differ if you are using PX4 firmware or ArduPilot firmware.
ArduPilot Camera Setup
PX4 Camera Setup
For more information see Camera (PX4 User Guide).
The camera settings section is not available by default for FMUv2-based flight controllers (e.g. 3DR Pixhawk) because the camera module is not automatically included in firmware. For more information see this topic.