Opencv light not turning off?

Question

Python

When sending a picture from the camera to the telegram bot, the light on the webcam does not turn off, if you run the code without the bot, the light turns off.

def cam(message):
  cap = cv2.VideoCapture(0)
  cap.set(3,1980)
  cap.set(4,1080)
  for i in range(5):
    cap.read()  
  ret, frame = cap.read()
  cv2.imwrite('cam.png', frame)   
  cap.release()