how to pass $task variable to blade file in laravel

I have following blade file as form.blade.php action=""> and My controller methods for saving is ```

 private function saveUploads(Request $request, $fileUrl, $id,$task)
    {

        $file = new File;
        $file->file_name  = $request->file('file_name')->getClientOriginalName();
        $file->file_url   = $fileUrl;
        $file->project_id = $id;

        $file->task_id = $task;


        $file->save();
    }

and My route is this

Route::post('projects/{projects}/files', [
     'uses' => 'FilesController@uploadAttachments',
     'as'   => 'projects.files',
     'middleware' => ['auth']
]);

but I got this error code here

Undefined variable: task (View: C:\Users\Jone\Desktop\ddd\resources\views\files\form.blade.php) 

via Chebli Mohamed