Model Point Particle Effect

https://playcanvas.com/editor/project/1338856


I am trying to implement the point particle effect in the model, but I don’t know where my current problem is. After running it, there is no effect. I tried to obtain the vertex data of the model and used a custom mesh shader, but it did not take effect. Can you help me check

There is something similar done here:
https://playcanvas.vercel.app/#/graphics/point-cloud