Flipbook in material play once?

I looked it up online, and only come across one real answer, but it caused another problem.

I am working on a thruster effect, and I want to have it shoot out a bunch of flame when I press the key, continue going while I hold it, then die off when I release the key. I have just about everything else taken care of, but when i bring in the material for the initial blast or the dying off flame, it starts at a random time in the flipbook and repeats. Naturally, I googled the answer, to find out I had to put a static boolean in the “Clamp Anim” input. When I did that, it only shows the last frame of the animation. Whether it be in the material viewport, on a mesh, in cascade, it doesn’t play the animation, and only stays on the last frame.

What am I doing wrong?

Thanks!