Custom shader has no shadow

Hello, I am not sure why but my custom shader, when applied to a material, doesn't make the GameObject able to cast shadows. This is the custom shader; what am I doing wrong?

 Shader "Custom/BlockShader"
 {
     Properties
     {
         [PerRendererData] _Color ("Color", Color) = (1,1,1,1)
         _MainTex ("Albedo", 2D) = "white" {}
         _Glossiness ("Smoothness", Range(0,1)) = 0.5
         _Metallic ("Metallic", Range(0,1)) = 0.0
     }
     SubShader
     {
         Tags {"Queue"="Transparent" "RenderType"="Transparent"}
         LOD 200
 
         CGPROGRAM
         // Physically based Standard lighting model, and enable shadows on all light types 
         #pragma surface surf Standard fullforwardshadows alpha
 
         // Use shader model 3.0 target, to get nicer looking lighting
         #pragma target 3.0
 
         sampler2D _MainTex;
 
         struct Input
         {
             float2 uv_MainTex;
         };
 
         half _Glossiness;
         half _Metallic;
         fixed4 _Color;
 
         // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
         // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
         // #pragma instancing_options assumeuniformscaling
         UNITY_INSTANCING_BUFFER_START(Props)
             // put more per-instance properties here
         UNITY_INSTANCING_BUFFER_END(Props)
 
         void surf (Input IN, inout SurfaceOutputStandard o)
         {
             // Albedo comes from a texture tinted by color
             fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
             o.Albedo = c.rgb;
             // Metallic and smoothness come from slider variables
             o.Metallic = _Metallic;
             o.Smoothness = _Glossiness;
             o.Alpha = c.a;
         }
         ENDCG
     }
     Fallback "Standard"
 }