Even out a run with dotted rhythms
When a fast run comes out uneven, Dotted rhythms rewrites its notes as long–short pairs on the score and plays them to you once. You play them long–short twice and short–long twice, then the run as written. Only the run's hand is listened to; the other hand can play along or rest.
After a take, choose Practice in dotted rhythms
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 four takes
The score shows the rhythm to play: long–short twice, then short–long twice. After each take you see whether every note was there and each long note came out longer than its short one; if not, you play that take once more.
Play the run as written
The score goes back to the written rhythm, and this take carries on your practice of the spot at the same speed. Start dotted rhythms again whenever you like, or simply keep repeating.
Playing a run in other rhythms is a long-standing way teachers use to even out fast passages. Moving the long note from the first note of each pair to the second keeps a stop from settling into one place, and finishing in the written rhythm brings the run back to how you will play it.