How to change size/scale of particles in a particle shader?

Help
1

Godot Version

4.3

Question

I can’t figure out how to change the size/scale of particles through a particle shader using GPUParticles2D. I can edit the TRANSFORM matrix, but if I do this in the process() function it scales the particles every frame. If i edit the TRASNFORM in the start() function, it seems to scale the particles every LIFETIME (i assume when the particles die and get re-instantiated). Any help is appreciated, thank you.