Error in Custom Vertical Gradient Shader: "Can not find vertex attribute: a_texCoord"

Cocos Creator
1

I have made an effect to apply the vertical gradient on node but I am getting the following error:
W/renderer (1056): Can not find vertex attribute: a_texCoord

This is the code for the effect file used:

CCEffect %{
  properties:
    texture: { value: white, editor: { type: texture } }  # Texture property
    alphaThreshold: { value: 0.5 }

  techniques:
  - passes:
    - vert: vs
      frag: fs
      blendState:
        targets:
        - blend: true
      rasterizerState:
        cullMode: none
        depthStencilState:
          depthTest: true
          depthWrite: true
}%

CCProgram vs %{
    precision mediump float;

    // Uniform block for matrix uniforms
    uniform MatBlock {
        mat4 cc_matViewProj; // Matrix uniform
    };

    // Attributes for vertex position and texture coordinates
    attribute vec3 a_position;  
    attribute vec2 a_texCoord;  // Ensure this matches your model's vertex attributes

    // Varying to pass texture coordinates to the fragment shader
    varying vec2 v_texCoord;

    void main() {
        gl_Position = cc_matViewProj * vec4(a_position, 1.0);
        v_texCoord = a_texCoord;  // Pass the texture coordinates
    }
}%

CCProgram fs %{
    precision mediump float;

    // Uniform block for color
    uniform ColorBlock {
        vec4 color;  // Non-sampler uniform for color
    };

    // Sampler uniform for texture
    uniform sampler2D texture;  

    // Varying to receive texture coordinates
    varying vec2 v_texCoord;

    void main() {
        // Sample the texture
        vec4 texColor = texture2D(texture, v_texCoord);

        // Create a vertical gradient using the y-coordinate
        float gradient = v_texCoord.y;

        // Mix the sampled texture color with the gradient color
        vec4 gradientColor = mix(vec4(1.0, 1.0, 1.0, 1.0), color, gradient);

        // Output the final fragment color
        gl_FragColor = texColor * gradientColor;
    }
}%

Can someone help me with this issue? How can I solve it or if there is some better way to my problem.