How to make the non-illuminated side of the object illuminated? Shader and Normals

I am writing a surface shader. How to make the non-illuminated side of the object illuminated? The object should be lit evenly from all sides! Illumination of the object should not depend on the position or rotation of the object. I managed to achieve the desired result, but it only works on the Particle system. It must be the surface shader, because I need the emission parameter.

 Shader "Custom/Illuminate" 
 {
     Properties
     {
         _MainTex("Texture", 2D) = "white" {}
         [HDR]_Color("Color", Color) = (1,1,1,1)
         _Glossiness("Smoothness", Range(0,1)) = 0.5
         _Metallic("Metallic", Range(0,1)) = 0.0
         _Emission("Emission", Range(0,10)) = 0.0
         [HDR]_EmissionColor("EmissionColor", Color) = (1,1,1,1)
     }
     SubShader
         {
             Tags { "RenderType" = "Opaque" "IgnoreProjector" = "True" }
             LOD 200
 
             CGPROGRAM
 
             #include "UnityCG.cginc"
             #pragma surface surf Standard vertex:vert 
             #pragma target 3.0
 
             sampler2D _MainTex;
 
             struct Input
             {
                 float2 uv_MainTex;
             };
 
             half _Glossiness;
             half _Metallic;
             fixed4 _Color;
             float _Emission;
             fixed4 _EmissionColor;
 
             void vert(inout appdata_full v, out Input o)
             {
                 UNITY_INITIALIZE_OUTPUT(Input,o);
                 v.normal = normalize(WorldSpaceLightDir(v.vertex));
 
             }
 
             void surf(Input IN, inout SurfaceOutputStandard o)
             {
                 fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
                 c *= c.a;
                 o.Albedo = c.rgb;
                 o.Metallic = _Metallic;
                 o.Smoothness = _Glossiness;
                 o.Emission = _EmissionColor*_Emission;
                 o.Alpha = c.a;
                 
             }
             ENDCG
         }
         FallBack "VertexLit"
 }

Left - Particle System, Right - Mesh

if I add a tag: Tags { "LightMode"="ForwardBase"} then everything works the other way around and a black duplicate of the object appears.