Even out a run by changing dynamics
When a fast run in one hand comes out uneven, Changing dynamics writes a crescendo hairpin over the run on the score and plays it to you once, growing louder. You play the run growing louder, then growing softer, then as written. Only the run's hand is listened to; the other hand can play along or rest.
After a take, choose Practice with changing dynamics
It's right under the button that polishes those bars in the result; if that button shows another drill, pick it from Other practice next to it. While you're practising a spot, Other practice in the bar at the bottom opens it too.
Listen once, then play the run growing louder, then softer
The score shows a hairpin over the run. In the first take, start soft and grow louder to the end of the run; in the second, the hairpin closes into a diminuendo: start strong and grow softer to the end. How loud you play is up to you; what's listened for is whether the end comes out louder, or softer, than the start. After each take you see whether every note was there and the run grew the right way; if it didn't, the result says in which bar and you play that take once more.
Play the run as written
The hairpin is gone, the score is back to how it's written, and you see whether the run came out more even than at first. This take carries on your practice of the spot at the same speed. Start changing dynamics again whenever you like, or simply keep repeating.
Playing a run louder and softer on purpose makes each finger choose how much weight to give every note, instead of letting the strong fingers hammer and the weak ones fade away. That control over each note is what an even run needs. Shaping the run both ways, growing and fading, keeps one habit from setting in, and finishing as written shows the gain where it counts.