FileDownloadWorker.kt

private fun getSavedFileUri(
        fileName:String,
        fileType:String,
        fileUrl:String,
        context: Context): Uri?{
        val mimeType = when(fileType){
            "PDF" -> "application/pdf"
            "PNG" -> "image/png"
            "MP4" -> "video/mp4"
            else -> ""
        } // different types of files will have different mime type

        if (mimeType.isEmpty()) return null

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q){
            val contentValues = ContentValues().apply {
                put(MediaStore.MediaColumns.DISPLAY_NAME, fileName)
                put(MediaStore.MediaColumns.MIME_TYPE, mimeType)
                put(MediaStore.MediaColumns.RELATIVE_PATH, "Download/DownloaderDemo")
            }

            val resolver = context.contentResolver

            val uri = resolver.insert(MediaStore.Downloads.EXTERNAL_CONTENT_URI, contentValues)

            return if (uri!=null){
                URL(fileUrl).openStream().use { input->
                    resolver.openOutputStream(uri).use { output->
                        input.copyTo(output!!, DEFAULT_BUFFER_SIZE)
                    }
                }
                uri
            }else{
                null
            }

        }else{

            val target = File(
                Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),
                fileName
            )
            URL(fileUrl).openStream().use { input->
                FileOutputStream(target).use { output ->
                    input.copyTo(output)
                }
            }

            return target.toUri()
        }
    }