JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/4.0.0-beta.12/fabric.js"></script>

<div id="lemu">
    
    <canvas id='mycanvas' width='400' height='400' style='border:1px solid #000000;'></canvas>
    <img src='' style="border:1px solid">
</div>

<div class="japu">click to copy the canvas </div>

<select><option value="1x1">36x24</option> <option value="36x48">36x24</option>  <option value="36x48">36x96</option> </select>

JavaScript

$=jQuery;
  
  $(document).ready(function () {
        jQuery('.japu').click(function(){

         var canstring = canvas.toDataURL();
         
         jQuery('img').attr('src',canstring);   

          });

fabric.StaticCanvas.prototype.toCanvasElement =  function(multiplier, cropping) {
      multiplier = multiplier || 1;
      cropping = cropping || { };
      var scaledWidth = (cropping.width || this.width) * multiplier,
          scaledHeight = (cropping.height || this.height) * multiplier,
          zoomX = canvas.viewportTransform[0],
          zoomY = canvas.viewportTransform[3],
          originalWidth = this.width,
          originalHeight = this.height,
          newZoomX = zoomX * multiplier,
          newZoomY = zoomY * multiplier,
          vp = this.viewportTransform,
          translateX = (vp[4] - (cropping.left || 0)) * multiplier,
          translateY = (vp[5] - (cropping.top || 0)) * multiplier,
          originalInteractive = this.interactive,
          newVp = [newZoomX, 0, 0, newZoomY, translateX, translateY],
          originalRetina = this.enableRetinaScaling,
          canvasEl = fabric.util.createCanvasElement(),
          originalContextTop = this.contextTop;
      canvasEl.width = scaledWidth;
      canvasEl.height = scaledHeight;
      this.contextTop = null;
      this.enableRetinaScaling = false;
      this.interactive = false;
      this.viewportTransform = newVp;
      this.width = scaledWidth;
      this.height = scaledHeight;
      this.calcViewportBoundaries();
      this.renderCanvas(canvasEl.getContext('2d'), this._objects);
      this.viewportTransform = vp;
      this.width = originalWidth;
      this.height = originalHeight;
      this.calcViewportBoundaries();
      this.interactive = originalInteractive;
      this.enableRetinaScaling = originalRetina;
      this.contextTop = originalContextTop;
      return canvasEl;
};
    
window.canvas = new fabric.Canvas('mycanvas');
...