How to give a new RNG seed to each instance for in geometry nodes?

This is done using Blender 3.0. I have a very simple geometry node setup with a main trunk which has branches. Now the main trunk is a mesh but branches only curves to keep it simple.

Each branch should have random displacement from random value node. The problem here is that now each branch is random but they all are identical to each other.

Q: How can I give a unique seed for each branch so that they are uniquelly random?

Basically I’d guess each instance has a unique ID or index and I could feed that to the random value node. But I have no clue how to do it. All tips are welcome.

why dont using a noise texture in world coordinates to displace your points?

So, how would that work? How do I maintain se same control and achieve the same results that way? Ie. I want to displace the points along the z-axis of the branches on xy-plane only.