Accessing vertex position in surf directly without vert's out parameter

I have problem with output vertex In Tesselation Shader How can I fix it? https://forum.unity3d.com/threads/accessing-vertex-position-in-surf-directly-without-verts-out-parameter.432333/

    Shader "Tessellation Sample" {
                 Properties {
                     _EdgeLength ("Edge length", Range(2,50)) = 15
                     _MainTex ("Base (RGB)", 2D) = "white" {}
                     _DispTex ("Disp Texture", 2D) = "gray" {}
                     _NormalMap ("Normalmap", 2D) = "bump" {}
                     _Displacement ("Displacement", Range(0, 1.0)) = 0.3
                     _Color ("Color", color) = (1,1,1,0)
                     _SpecColor ("Spec color", color) = (0.5,0.5,0.5,0.5)
                 }
                 SubShader {
                     Tags { "RenderType"="Opaque" }
                     LOD 300
                     
                     CGPROGRAM
                     #pragma surface surf BlinnPhong addshadow fullforwardshadows vertex:disp tessellate:tessEdge nolightmap
                     #pragma target 4.6
                     #include "Tessellation.cginc"
         
                     float _EdgeLength;
         
                     float4 tessEdge (appdata_full v0, appdata_full v1, appdata_full v2)
                     {
                         return UnityEdgeLengthBasedTess (v0.vertex, v1.vertex, v2.vertex, _EdgeLength);
                     }
         
                     float _Displacement;
         
         
                     struct Input {
                         float4 position  : POSITION;
                         float3 worldPos  : TEXCOORD2;    // Used to calculate the texture UVs and world view vector
                         float4 proj0        : TEXCOORD3;    // Used for depth and reflection textures
                         float4 proj1     : TEXCOORD4;    // Used for the refraction texture
                     };
         
                     void disp (inout appdata_full v, out Input o){
                     UNITY_INITIALIZE_OUTPUT(Input,o);
                     o.worldPos = v.vertex.xyz;
                     o.position = UnityObjectToClipPos(v.vertex);
                     o.proj0 = ComputeScreenPos(o.position);
                     COMPUTE_EYEDEPTH(o.proj0.z);
                 
                     o.proj1 = o.proj0;
                     #if UNITY_UV_STARTS_AT_TOP
                     o.proj1.y = (o.position.w - o.position.y) * 0.5;
                     #endif
                     }
         
                     sampler2D _MainTex;
                     sampler2D _NormalMap;
                     fixed4 _Color;
         
                     void surf (Input IN, inout SurfaceOutput o) {
                         o.Albedo = float4(0,0,0,0);
                     }
                     ENDCG
                 }
                 FallBack "Diffuse"
             }

how can I fix it Shader error in 'Tessellation Sample': 'disp': no matching 1 parameter function at line 230 (on d3d11)