Unable using additional texture in effect composer

Add spot.png to global composer renderer. why? because i want to use photoshop blend shader deal the image.

var texture = new THREE.TextureLoader().load( `./effect.png` );

THREE.CustomShader = {

	uniforms: {
		"tDiffuse": { value: null },
		"u_texture": { value: texture },
        "u_resolution" :{ value: new THREE.Vector2() }

	vertexShader: [
		"varying vec2 vUv;",
		"void main() {",
			"vUv = uv;",
			"gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",


	].join( "\n" ),
        #ifdef GL_ES
            precision mediump float;

        uniform sampler2D tDiffuse;
        uniform sampler2D u_texture;
        uniform float u_time;

        void main(){
            vec2 uv = gl_FragCoord.xy / u_resolution.xy;

            gl_FragColor = texture2D( u_texture, uv );

But i just can see the black screen? how to do this? THX.

Can you please share an entire working example like a fiddle (https://jsfiddle.net/f2Lommf5/) or a git repository? It’s not possible to see from your current code snippet what’s going wrong.

Like this website link
It’s render by effect composer, i want add other texture to shader composer, i don’t want to use composer overlay.