How would I convert this fixed tessellation shader from CG into HLSL so it can be used with URP?

https://docs.unity3d.com/Manual/SL-SurfaceShaderTessellation.html

About a quarter of the way through this link, there's code to a fixed amount of tessellation shader that works perfectly for what I'm trying to do, but it's not compatible with the Universal Render Pipeline. I tried changing the "CGPROGRAM" and "ENDCG" to their hlsl counterparts, but that hasn't quite fixed it. I'd there's still a bit more refactoring that needs to happen, so any help is greatly appreciated.