Make shader outer glow wider

I failed to guess how could I make it glow wider with Unity UI image component.. I have zero knowledge about shaders I've got this script from the internet

 <code>
 Shader "Sprites/Cheap Outer Glow"
 {
     Properties
     {
         [PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
         _Color("Tint", Color) = (1,1,1,1)
         _GlowScale("Glow Scale", Range(0,2)) = 1
         _GlowColor("Glow Color", Color) = (1,1,1,1)
         [MaterialToggle] PixelSnap("Pixel snap", Float) = 0
     }
 
         SubShader
     {
         Tags
     {
         "Queue" = "Transparent"
         "IgnoreProjector" = "True"
         "RenderType" = "Transparent"
         "PreviewType" = "Plane"
         "CanUseSpriteAtlas" = "True"
     }
 
         Cull Off
         Lighting Off
         ZWrite Off
         Blend One OneMinusSrcAlpha
 
         Pass
     {
         CGPROGRAM
 #pragma vertex vert
 #pragma fragment frag
 #pragma target 2.0
 #pragma multi_compile _ PIXELSNAP_ON
 #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
 #include "UnityCG.cginc"
 
         struct appdata_t
     {
         float4 vertex   : POSITION;
         float4 color    : COLOR;
         float2 texcoord : TEXCOORD0;
     };
 
     struct v2f
     {
         float4 vertex   : SV_POSITION;
         fixed4 color : COLOR;
         float2 texcoord  : TEXCOORD0;
     };
 
     fixed4 _Color;
 
     v2f vert(appdata_t IN)
     {
         v2f OUT;
         OUT.vertex = UnityObjectToClipPos(IN.vertex);
         OUT.texcoord = IN.texcoord;
         OUT.color = IN.color * _Color;
 #ifdef PIXELSNAP_ON
         OUT.vertex = UnityPixelSnap(OUT.vertex);
 #endif
 
         return OUT;
     }
 
     sampler2D _MainTex;
     sampler2D _AlphaTex;
 
     fixed _GlowScale;
     fixed4 _GlowColor;
 
     fixed4 SampleSpriteTexture(float2 uv)
     {
         fixed4 color = tex2D(_MainTex, uv);
 
 #if ETC1_EXTERNAL_ALPHA
         // get the color from an external texture (usecase: Alpha support for ETC1 on android)
         color.a = tex2D(_AlphaTex, uv).r;
 #endif //ETC1_EXTERNAL_ALPHA
 
         return color;
     }
 
     fixed4 frag(v2f IN) : SV_Target
     {
         fixed4 c = SampleSpriteTexture(IN.texcoord) * IN.color;
 
     // Use alpha assuming glow is a gradient from 0.0 to ~0.75% alpha, and the rest is the sprite.
     fixed spriteAlpha = saturate(c.a * 4.0 - 3.0);
     fixed glowAlpha = saturate(1.0 - (1.0 - c.a / 0.75) / max(_GlowScale, 0.01)) * saturate(_GlowScale * 32.0);
     c.a = max(spriteAlpha, glowAlpha * _GlowColor.a);
     c.rgb = lerp(_GlowColor.rgb, c.rgb, 1.0 - (1.0 - saturate(spriteAlpha / max(_GlowColor.a, 0.01))) * saturate(_GlowScale * 32.0));
 
     c.rgb *= c.a;
     return c;
     }
         ENDCG
     }
     }
 }
 </code>