I see. The package comes with a Shader Graph shader that should work on all pipelines (on Assets/Shader/URP > poorly named). Can you make sure you have the Shader Graph package installed? Alternatively, the shader Doodle Studio ships with is nothing special: you can make your own material with any other shader that uses a texture and alpha (like Mobile/Particles/Alpha Blended) and the animation will show. Email is fernando.ramallo@gmail.com.