startDownload abstract method
Starts a file download operation in the background.
The download continues even if the app moves to the background. Progress can be tracked using getDownloadProgress.
Parameters:
fileUrl: The URL of the file to downloadsavePath: Local path where the downloaded file should be savedheaders: Optional HTTP headers to include in the request
Returns a task ID string that can be used to track progress or cancel the task.
Throws an Exception if the download fails to start.
Implementation
Future<String> startDownload({
required String fileUrl,
required String savePath,
Map<String, String>? headers,
});