Start an exhibition match. 1v1 against no bots. Sit and wait for the ball to stop bouncing. Make sure you are straight on from the opponent’s hoop. Drive straight into the ball. No boost or you’ll hit too hard. The ball will go in every time. Do it twice in a row and you’ll get the trophy.
You don’t need to mess around with modifiers and modes. Only thing that might help a little is making the ball lighter, but it should be easy regardless.