Using openCV to overlay transparent image onto another image

How can I overlay a transparent PNG onto another image without losing it's transparency using openCV in python?

import cv2

background = cv2.imread('field.jpg')
overlay = cv2.imread('dice.png')

# Help please

cv2.imwrite('combined.png', background)

Desired output:

Sources:

Background Image

Overlay

import cv2

background = cv2.imread('field.jpg')
overlay = cv2.imread('dice.png')

added_image = cv2.addWeighted(background,0.4,overlay,0.1,0)

cv2.imwrite('combined.png', added_image)