How to get smooth shading on a cone?

Someone is flexing their secret for smooth cone shading. Apparently, they achieved this through shaders, without making the geometry more complex. Does anyone know how to set this up? Thank you

Ask the person that made the video?

He is not interested in sharing the secret

Well, I’d assume this is just standard radial normals…in which case there’s not much “secret” about it. LOL