3ds max python, execute python script on each render frame

Question

I'm trying to change material per frame per render. Any idea how to create callback/function/action so that I can execute the python script per render frame?

So far this does not work :

print("Hello Python")

rt =  pymxs.runtime

o = rt.callbacks.removeScripts(id=rt.name("Hello"))
print(o)


def doAnimation(a=0,b=0,c=0):
    print("lalala is : ",a,b,c)
    return True
    
o = rt.callbacks.addScript(rt.Name("preRenderFrame"), doAnimation, persistent=rt.true, id=rt.Name("Hello"))
print(o)
print(rt.callbacks.show(id=rt.Name("Hello"), asArray=True))

Regards Dariusz