Using node-canvas on NextJS API route

[Corouna]

As titled

Im using the node-canvas library here - https://github.com/Automattic/node-canvas

The idea here is that the API will receive the b64 image, and push it to the canvas for processing, before saving the image and returning the processed image back to the user.

The codes for the API is this

import Canvas from 'canvas';
import path from 'path';
import fs from 'fs';

/* Download API config */
export const config = {
  api: {
    bodySizeLimit: '10mb',
    bodyParser: {
      sizeLimit: '10mb',
    }
  }
};

export default (req, res) => {
  const { file, filename } = req.body;

  processImage(file, b64 => {
    fs.writeFile(absolutepathtofolder + filename, b64, { encoding: 'base64' }, function (err) {
      if (err) return console.log(err);
      let imageBuffer = fs.readFileSync(path);
      res.setHeader('Content-Type', 'image/jpg');
      res.send(imageBuffer);
    });
  });
}

const processImage = (b64, cb) => {
  let img = new Canvas.Image();

  img.onload = function () {
    let oc = new Canvas.createCanvas(),
        octx = oc.getContext('2d'),
        iWidth = img.naturalWidth,
        iHeight = img.naturalHeight;

    /* Some process in here */

      cb(processedB64);
  }
  img.src = b64;
}

Problem here is that, i can't seem to make the canvas work. It did call the processImage but when going to img.onload, nothing happened. This same code above works in NodeJs + ExpressJs, but not in NextJs API.

Need help here if there's anything that i missed here.