Float Animation From Current Z Axis

Hi,
I’ve been having this problem for the longest and I can’t figure out how to do it.
I want to make an animation that when a button is pressed the player will float for 2 seconds, from the current position, and when it’s finished he will fall to the ground.
Probably the problem are the methods I used.

1st Method:
This one works perfectly but the problem is that the animation always start on the Z axis that I put on the first key.
And another problem is that, since my game is based on platforms where the player can fall, with this method the player won’t be able to start the animation when he’s falling.


2nd method:
I’ve tried using the lerp node using the current z axis and the same variable as before but +2, so it go up.
This works perfect too but the only problem is that it doesn’t start from the ground and doesn’t finish on the ground but the coordinates are the same of the initial coordinates. I’ve tried debugging with prints and it looks alright but not visually.