Controlling animation frame by frame from script

Hi there,

A Unity and C# newbie. I am trying to take screenshot at each keyframe of an animation. As far as I can understand from google and unity answers searches using anim["animation_name"].normalizedTime = time is the way to go. However my animation doesn't change its state with it. I enable animation at the void Start() and using Animation. Here is the code:

 for(double j=0;j<1;j+=0.1)
             {
                 
                 anim["T2B"].normalizedTime += 0.1f;
                 CaptureNamedScreenshot();
             }

Also I tried to manually set times of animations manually and take screenshots, I cannot do that either. It only took one screenshot.

 anim["T2B"].enabled = true;
 anim["T2B"].normalizedTime = 0.5f;
 CaptureNamedScreenshot();
 anim["T2B"].normalizedTime = 0.9f;
 CaptureNamedScreenshot();

Is there a better way? Thank you for your time