Kesha has a cameo as a "Spirit Girl".
The cameo was a "crazy coincidence," Lowery says. "(A) friend was at a party that Kesha just happened to be at and was like, 'Hey, I've got some friends in Texas and they want you to be in their movie.' Two days later, she flew to Texas and did it. It was so last-minute and spontaneous that I was really worried that she'd get there and be disappointed and realize that she had very little to actually do in that scene. But we wanted her to be there. Thankfully, she did it and had a blast." In the scene, professional magician Jared Kopf does magic tricks for Kesha, who is credited as "Spirit Girl" in the movie.
Source: USA Today