Need help i can't figure something out in the practice range,

hello all I've been wanting to practice against different ults in the practice range but i can't figure out how to make the bots use their ults. I've seen videos of people fighting three ulting Wandas in the practice range and i just can't get it to work i would appreciate some one explaining this to me or even showing me a video on how to do it. I've looked everywhere and can't get it to work.