public function fileUploadPost(Request $request)
{
$request->validate([
'file' => 'required|mimes:pdf,xlx,csv|max:2048',
]);
$fileName = time().'.'.$request->file->extension();
$request->file->move(public_path('uploads'), $fileName);
return back()
->with('success','You have successfully upload file.')
->with('file',$fileName);
}