node js getQuiz function

function getQuestion(req, res) {
    const id = req.params.id;

    Question.findOne({
      _id: id
    }, (err, question) => {
      if (err) {
        res.status(500).json({
          success: false,
          error: err,
          message: "server error"
        });
      } else if (question) {
        res.status(200).json({
          success: true,
          question
        });
      } else {
        res.status(404).json({
          success: false,
          message: 'page not found'
        })
      }
    })
  }