animate asset warping

Hello. I'm new to Animate and I am trying to do a lesson with my high school students. I want them to be able to animate a character they created in Illustrator. I've gone through all the steps of the different layers and making each layer a symbol, but am having no luck using the asset warp tool on my character. I just get the small circle with the slash on it when i grab it and try to plant a pivot point. Anone have any insight? Thanks!!