How to wait for a file to be created before trying to read it in node.js?

Question

I am creating an image with GraphicsMagick and then I would like to wait for it to be created before reading it, this is what I have tried:

const fs = require('fs');
const { v5: uuidv5 } = require('uuid');

const readImage = async path => {
  let uuid = uuidv5(path, uuidv5.DNS);
  let path2 = 'images/' + uuid + '.png';

  await gm(path).setFormat("png").colorspace('gray').write(path2, function (error) {
    if (!error)
      console.log("Finished converting " + path);
    else
      console.error(error);
  });

  const imageBuffer = await fs.readFileSync(path2);
  return imageBuffer;
}

but currently it tries to read it before it is written to disk causing

UnhandledPromiseRejectionWarning: Error: ENOENT: no such file or directory

Thanks in advance for the answers