For precision movement over time, I like to lerp a set origin and destination over a timer duration. You'll need the timer behavior, and two instance variables for the original position and the destination position.
For the jump gravity motion, a simple inverted quadratic equation should simulate it fairly well. It would be y=1-4(x-0.5)^2 in this case, where the x value of lerp will go up to 1 and back down to 0 on a parabolic curve based on the amount of time passed over the total timer duration.
Here is what the events should look like:
+ Keyboard: On any key pressed
+ Sprite: [X] Is Timer "jump" running
-> Sprite: Start Timer "jump" for 1.0 (Once)
-> Sprite: Set OriginY to Self.Y
-> Sprite: Set TargetY to Self.Y-100
+ Sprite: Is Timer "jump" running
-> Sprite: Set Y to lerp(Sprite.OriginY,Sprite.TargetY,1-4×(Sprite.Timer.CurrentTime("jump")÷Sprite.Timer.Duration("jump")-0.5)^2)
The qarp expression could probably be used to simplify the equation but I never really wrapped my head around it... It could probably also be useful if you wanted to fine tune the motion.