RPi IR-CUT Camera works on Normal Mode by default. There are two ways to toggle between Normal Mode and Night-vision Mode.
1. By editing the config.txt file:
sudo nano /boot/config.txt
exit with save and restart your Pi then the camera will work on Night-vision Mode.
To revert to the Normal Mode, please remove the line disable_camera_led=1 then save and restart your Pi.
2. By changing the level on this position:
Thus, you can connect the GPIO from your Pi to this position, and toggle modes by changing the GPIO logic level. (HIGH --> Normal Mode, LOW --> Night-vision Mode)