Button element rendered twice using Paper.js

Question

Hi wondered if you could see why my button element is rendered twice. The function is called inside image.on('load',function(){}). Here is a pen and the code below. Thank you.

import paper from "https://esm.sh/paper";

window.onload = setup;
let buttonWrapper = null

function setup() {
  paper.setup('canvas');
buttonWrapper = document.querySelector('.button-wrapper');
  const image = new paper.Raster({
    source: 'https://assets.codepen.io/1070/texture_planet_earth_color_color.jpg',
    position: paper.view.center,
  });

  image.on('load', function () {
    console.log("the original size of the image", image.width);
    paper.project.view.viewSize = new paper.Size(image.width, image.height);
    setImageSize(image, 220, paper.view.size);
    paper.project.activeLayer.position = paper.view.center;
    
    // Call download function after setImageSize
   
  });

  image.onError = function () {
    console.log('image error');
  };
}

function setImageSize(img, targetWidth, canvas) {
  const canvasSize = Math.min(canvas.width, canvas.height);
  const gridSize = canvasSize / 120;
  const spacing = gridSize / 18;
  const originalWidth = img.width;
  const originalHeight = img.height;
  img.crossOrigin = "";
  const originalAspectRatio = originalWidth / originalHeight;
  const newWidth = targetWidth;
  const newHeight = targetWidth / originalAspectRatio;

  img.size = new paper.Size(newWidth, newHeight);

  img.position = paper.project.view.center;

  // Clear existing spots
  paper.project.activeLayer.removeChildren();
        download(buttonWrapper);
  for (let x = 0; x < img.width; x++) {
    for (let y = 0; y < img.height; y++) {
      let color = img.getPixel(x, y);
      const spot = new paper.Path.Circle({
        center: new paper.Point(x * gridSize, y * gridSize),
        radius: gridSize / 2 / spacing,
        fillColor: 'black',
      });
      spot.scale(1 - color.gray);
    }
  }
  paper.project.activeLayer.position = paper.view.center;


}

function download(wrapper) {
  console.log('function run')
  const button = document.createElement('button');
 
  button.textContent = "Download";
  wrapper.append(button);
}