I want to animate WITHOUT easing. How can I make an element disappear upon reaching a keyframe?

[jor...@rethincadvertising.com]

Long story short. I am trying to mimic a "typing animation". I have a word typed out, and on top of each letter, I have a white block on top. When the timeline reaches a desired keyframe, I want the opacity on said block to go from 1 to 0, thus making the white block transparent and revealing the letter underneath.

However, I don't want the opacity to fade. I want it to be visible one frame, then invisible the next. It seems that this is impossible with Google Web Designer and that all animations have eases on them by default.

What am I missing? If I need to resign and go back to Adobe Animate, I'll reluctantly do so.