How to convert image from png to jpg in jimp?

I read the docs: https://github.com/oliver-moran/jimp

But could not find how to convert an image from png to jpg.

I must have missed something obvious.

Using jimp on my server with Node.js.

Here's my code:

image.scaleToFit(500, 500, Jimp.RESIZE_BICUBIC).quality(60).write("./public/images/uploads/thumb"+req.file.filename, function(err) {