Toon Basic Shader that can receive shadows

Hi everyone, I would like to know if it's possible to make this shader receive shadows, it's the Toon/Basic shader from unity, here is the code:

 Shader "Toon/Basic" {
     Properties {
         _Color ("Main Color", Color) = (.5,.5,.5,1)
         _MainTex ("Base (RGB)", 2D) = "white" {}
         _ToonShade ("ToonShader Cubemap(RGB)", CUBE) = "" { Texgen CubeNormal }
     }
 
 
     SubShader {
         Tags { "RenderType"="Opaque" }
         Pass {
             Name "BASE"
             Cull Off
             
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma fragmentoption ARB_precision_hint_fastest 
 
             #include "UnityCG.cginc"
 
             sampler2D _MainTex;
             samplerCUBE _ToonShade;
             float4 _MainTex_ST;
             float4 _Color;
 
             struct appdata {
                 float4 vertex : POSITION;
                 float2 texcoord : TEXCOORD0;
                 float3 normal : NORMAL;
             };
             
             struct v2f {
                 float4 pos : POSITION;
                 float2 texcoord : TEXCOORD0;
                 float3 cubenormal : TEXCOORD1;
             };
 
             v2f vert (appdata v)
             {
                 v2f o;
                 o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
                 o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
                 o.cubenormal = mul (UNITY_MATRIX_MV, float4(v.normal,0));
                 return o;
             }
 
             float4 frag (v2f i) : COLOR
             {
                 float4 col = _Color * tex2D(_MainTex, i.texcoord);
                 float4 cube = texCUBE(_ToonShade, i.cubenormal);
                 return float4(2.0f * cube.rgb * col.rgb, col.a);
             }
             ENDCG            
         }
     } 
 
     SubShader {
         Tags { "RenderType"="Opaque" }
         Pass {
             Name "BASE"
             Cull Off
             SetTexture [_MainTex] {
                 constantColor [_Color]
                 Combine texture * constant
             } 
             SetTexture [_ToonShade] {
                 combine texture * previous DOUBLE, previous
             }
         }
     } 
     
     Fallback "VertexLit"
 }