If you want to know how to jump in Roblox when you play from your computer, then you have to see this…
how to jump in Roblox using the keyboard
To play Roblox on pc you just have to use the controls that point to the start of the game.
Use WASD keys to move in up, down, left or right direction.
But pTo jump you need to press the space bar, as shown in the following video: