createShader with texture not working

p5.js Coding Questions
1

Hi, the following example works if instead of using createShader() in setup() I use loadShader() in preload(), but I need to use createShader because I need the shader code to be in the script file. Is there something I’m doing wrong? Why createShader does not work with textures?

// this variable will hold our shader object
 let theShader;
 // this variable will hold our createGraphics layer
 let shaderTexture;

 let theta = 0;
 
 let vert = `
    attribute vec3 aPosition;
    void main() {
      vec4 positionVec4 = vec4(aPosition, 1.0);
      positionVec4.xy = positionVec4.xy * 2.0 - 1.0; 
      gl_Position = positionVec4;
    }
  `;

  let frag = `
    void main() {
      gl_FragColor = vec4(1.0, 0.5, 0.25, 1.0);
    }
  `;

 let x;
 let y;
 let outsideRadius = 200;
 let insideRadius = 100;

 function preload(){
   // load the shader
   //theShader = loadShader('assets/texture.vert','assets/texture.frag');
 }

 function setup() {
   // shaders require WEBGL mode to work
   createCanvas(710, 400, WEBGL);
   noStroke();
   theShader = createShader(vert,frag);

   // initialize the createGraphics layers
   shaderTexture = createGraphics(710, 400, WEBGL);

   // turn off the createGraphics layers stroke
   shaderTexture.noStroke();

    x = -50;
    y = 0;
 }

 function draw() {

   // instead of just setting the active shader we are passing it to the createGraphics layer
   shaderTexture.shader(theShader);

   // here we're using setUniform() to send our uniform values to the shader
   theShader.setUniform("resolution", [width, height]);
   theShader.setUniform("time", millis() / 1000.0);
   theShader.setUniform("mouse", [mouseX, map(mouseY, 0, height, height, 0)]);

   // passing the shaderTexture layer geometry to render on
   shaderTexture.rect(0,0,width,height);

   background(255);

Thanks