Set Distortion Strength of Unlit Particle Shader, how?

This particular feature of the Unlit Particle Shader doesn’t respond to the Animation Clip’s timeline. Therefore, to animated this value, need to access and set with a script.

How to do this with C#?

It’s not clear to me, which of the shaders properties do this, nor how to activate and then use the right one, and to set it via script.

Are you referring to Particles/Standard Unlit?

Properties are available/displayed in the Inspector:
I’m guessing you’re looking for “_DistortionStrength” or “_DistortionBlend”