Flying Boat/Any Mountable

Hello, I was wondering how to make boat or any mountable to be able to flight while a player sitting on it. I thought of using execute that detect player sitting on boat. Although, my only concern is that I actually have no idea how to detect when they press space and ctrl. Let say space for up and ctrl go down. Although, I do know that it is possible to make them forward by using execute with like "{Motion:[0.2,0.0,0.2]}" Like: execute as @a if entity @e[type=boat,distance=..1,limit=1] run data merge entity @e[type=boat,distance=..1,limit=1] {Motion:[0.2,0.0,0.2]}