how do I make shader material scroll per pixel?

Godot Version

4.2.1

Question

Hi, I wanted to create something similar to liquid textures from classic doom games for my project , but i don’t know how to make my texture scroll per pixel

here’s some example of what I’m trying to achieve
N4cXbR0

and here’s how my shader script looks like now
IMG_20240703_200112_724

thanks for any tips (and sorry for my english if there’s any mistakes)
!