Shadows in projector shader

I am trying to make custom shader for projector component, to make sticker for car. I improve standard ProjectorMultiply shadere to draw only in front of projector and in limited distance.

But I can't use shadows over this. I am trying standard ways, like here Vertex and fragment shader examples, and many other ways from different forums, but all of it not work.

I know that if I blend projection with background texture it will have shadow, but I need clean texture of sticker.

 Shader "Projector/Sticker" {
     Properties {
         _ShadowTex ("Cookie", 2D) = "gray" {}
         _ProjectorForward("Projector Forward", Vector) = (0, 0, 0)
         _ProjectorPosition("Projector Position", Vector) = (0, 0, 0)
         _Distance("Projector Distance", Float) = 5
 
         _Reflection("Reflection Intence", Float) = 1
     }
     Subshader {
         Tags {"Queue"="Transparent"}
         Pass {
             ZWrite Off
             ColorMask RGB
             Blend SrcAlpha OneMinusSrcAlpha
             Offset -1, -1
 
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma multi_compile_fwdbase nolightmap nodirlightmap nodynlightmap novertexlight
             #include "UnityCG.cginc"
             #include "UnityLightingCommon.cginc"
             #include "AutoLight.cginc"
             
             struct v2f {
                 float4 uvShadow : TEXCOORD0;
                 float3 normal : NORMAL; 
                 float4 pos : SV_POSITION;
                 float3 worldPos : NORMAL1;
                 fixed3 diff : COLOR;
             };
             
             float4x4 unity_Projector;
             float4x4 unity_ProjectorClip;
 
             v2f vert (appdata_base v)
             {
                 v2f o;
                 o.pos = mul (UNITY_MATRIX_MVP, v.vertex);
                 o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
                 o.uvShadow = mul (unity_Projector, v.vertex);
                 o.normal = mul(unity_ObjectToWorld, v.normal);
 
                 //Light
                 half nl = min(max(0.3, dot(o.normal, _WorldSpaceLightPos0.xyz) * 0.5 + 0.5), 0.8);
                 o.diff = nl * _LightColor0;
 
                 return o;
             }
             
             sampler2D _ShadowTex;
             sampler2D _FalloffTex;
             float3 _ProjectorForward;
             float3 _ProjectorPosition;
             float _Distance;
             float _Reflection;
 
             fixed4 frag(v2f i) : SV_Target
             {
                 fixed4 projectedCord = UNITY_PROJ_COORD(i.uvShadow);
                 clip(projectedCord.z);
 
                 if (distance(_ProjectorPosition, i.worldPos) > _Distance)
                     return float4(0, 0, 0, 0);
                 if (i.uvShadow.x > 1 || i.uvShadow.x < 0)
                     return float4(0, 0, 0, 0);
                 if (i.uvShadow.y > 1 || i.uvShadow.y < 0)
                     return float4(0, 0, 0, 0);
 
                 if (dot(i.normal, _ProjectorForward) < 0.0) // in front of projector?
                 {
                     fixed4 res = tex2Dproj(_ShadowTex, UNITY_PROJ_COORD(i.uvShadow));
                     UNITY_APPLY_FOG_COLOR(i.fogCoord, res, fixed4(1, 1, 1, 1));
 
                     return res * fixed4(i.diff, 1);
                 }
                 else // behind projector
                 {
                     return float4(1.0, 1.0, 1.0, 0.0);
                 }
             }
             ENDCG
         }
     }
 }
 

Here is example, black is a strengthened shadow