Download Firebase Storage

Until then I have this code but without success

  public void baixar(){
    FirebaseStorage storage = FirebaseStorage.getInstance();
    StorageReference storageRef = storage.getReferenceFromUrl("gs://the-xxxxxxxxxxlpha1.appspot.com/arquivos");
    StorageReference  islandRef = storageRef.child(nome+".pdf");

    File rootPath = new File(Environment.getExternalStorageDirectory(), "file_name");
        if(!rootPath.exists()) {
            rootPath.mkdirs();
        }

        final File localFile = new File(rootPath,"imageName.txt");

        islandRef.getFile(localFile).addOnSuccessListener(new OnSuccessListener<FileDownloadTask.TaskSnapshot>() {
            @Override
            public void onSuccess(FileDownloadTask.TaskSnapshot taskSnapshot) {
                Log.e("firebase ",";local tem file created  created " +localFile.toString());
                //  updateDb(timestamp,localFile.toString(),position);
            }
        }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception exception) {
                Log.e("firebase ",";local tem file not created  created " +exception.toString());
            }
        });
}

I think I'm passing wrong parameters, the documentation did not help me much.