On my 240D manual both are 14MM socket head (Allen type.)
Have you crawled underneath and looked? The fill plug is too close to the tunnel to get socket and ratchet in place. You can cut a piece off of a 14MM Allen and use a box end wrench on it. This will give you access.
Always remove the filler plug before the drain plug. The last thing you want to do is to remove the drain plug, drain the oil, then find that you have no way to refill it.