Setting and Animating Gradient Fill

Just for clarity, I am trying to reproduce a similar effect as seen in the motion gaphics intro for this clip, from 00:00 to 00:002






Notice how the NODE text fill proceeds downwards, filling in the alpha. Ultimately, I am trying to get my own Text Layer's opacity fill to not only increase in value, but the actual change in opacity to start at a certain point, and "spread"

In another thread, I specified my goal, and it was suggested to "Convert the text to a shape layer and animate the gradient fill, which has opacity stops as well as color stops."

I have converted the text layer into a shape layer, but I am still stuck:
I found the "gradient" button, but I have not found an "animate gradient" option.

Also, how can you adjust the status of the gradient?

Is there a way to make a gradient act as an alpha mask?

right now, all that I see is a solid black and white linear gradient with no option to set a "fade to alpha" gradient in the Fill settings.

And I have no idea where the menu to actually animate the gradient actually is.

thank you for the tip! at this point, I'm not entirely sure what I am doing wrong. I have set up the Ramp effect, but the stroke does not start off in an 'alpha mode' despite the keyframes I set for the ramp.

The stroke stays at 100% opacity no matter where I scrub on the timeline.