With epilogue / finale-rest, how can I accept binary files via multer?

I'm doing:

const audioResource = finale.resource({
    model: db.models.Audio,
    endpoints: ['/audios', '/audios/:id']
})

audioResource.use(multer().single("file"))
audioResource.use(resources.audio)

Where resources.audio is:

module.exports = {
    create: {
        write: {
            before: (req, res, context) => {
                console.log(Object.keys(req))
                console.log(req.body)
                console.log("HERE I AM!")
                console.log(req.file)
            }
        }
    }
}

However, I can't access req.file. Is it possible to set up with the multer middleware?

I think the right way to use it would be

module.exports = {
    create: {
        write: {
            before: (req, res, context) => {
                upload.single('file')(req, res, () => {
                  console.log(Object.keys(req))
                  console.log(req.body)
                  console.log("HERE I AM!")
                  console.log(req.file)
                }
            }
        }
    }
}