Shimano Claris 3x8 shifters with Claris 2x8 drivetrain
I have a fitness bike with a flat bar and Claris 2x8 shifters and drive train on it. I would like to convert it to a road bike by swapping the handle bar and its shifters with another one that comes with the Shimano Claris 2403 (8x3) on it. Are these compatible, or can they be adjusted so that they can be used with the 2x8 drivetrain?