Make rideable entity jump

Hi all,

I'm trying to make a simple skateboard mod, where you can just ride around on them and use them for transportation, nothing complicated.

But I have no idea how to make it so that when I press spacebar, you and the skateboard jump. The only questions I see online are about making them fly really. I've messed around with the keybind procedures and movement velocity, but no dice.

How can I do this?

Thanks!

(Bonus question if you really want to make my day. How can I change it so that the player is standing on the skateboard, and not sitting? Can't find anything about that either)