It does not write (save) the XML it takes from the server

I have an app that previously read an xml file from a server and saved it in the phone so that the user could see the content without internet connection, I have passed my application to kotlin and I find the error that the file no longer save it or write it in memory, previously I used this function in an Asyntask but where is the while I get an error and I could not solve it, thanks.

val conexion: HttpsURLConnection
        val urlArchivo: URL
        val url1 = "Mi URL"
        val fileOut: FileOutputStream
        val buffersize = 1024
        val buffer: ByteArray

        try {
            urlArchivo = URL(url1)
            conexion = urlArchivo.openConnection() as HttpsURLConnection
            conexion.readTimeout = 1000
            conexion.connectTimeout = 1000
            conexion.doInput = true
            conexion.requestMethod = "GET"
            conexion.connect()

            ruta = conexion.inputStream
            fileOut = FileOutputStream(archivo) // ubicacion archivo

            var bytesEscribir: Int
            buffer = ByteArray(buffersize)

            while ((bytesEscribir = ruta.read(buffer)) > 0) {

                fileOut.write(buffer, 0, bytesEscribir)
            }
            Toast.makeText(activity!!.applicationContext, getString(R.string.sinc_exitosa), Toast.LENGTH_LONG).show()
            ruta.close()
            fileOut.close()
            conexion.disconnect()