So I removed the airbag to have a look and it seems as
sirro said that the holes to mount the paddles are already there (red circles) and the 4 pins connector to the paddle is there too (blue circles).
Here is a photo of the paddles connector that match the connector I have on my wheel:
Are those paddles simple on/off switches? If so I could try to short the connector to simulate the paddle and see if the electronic is working before buying the paddles.