TypeError: data.forEach is not a function

[Tharvinash]

at exports.getScream:

exports.getScream = (req, res) => { let screamData = {}; db.doc(/screams/${req.params.screamId}) .get() .then((doc) => { if (!doc.exists) { return res.status(404).json({ error: 'Scream not found' }); } screamData = doc.data(); screamData.screamId = doc.id;

  return db
    .collection('comments')
    .orderBy('createdAt', 'desc')
    .where('screamId', '==', req.params.screamId)
    .get();
})
.then((data) => {
  screamData.comments = [];
  data.forEach((doc) => {
    screamData.comments.push(doc.data());
  });
 return res.json(screamData);
})
.catch((err) => {
  console.error(err);
  res.status(500).json({ error: err.code });
});

};

it says that TypeError: data.forEach is not a function. Is there a solution to solve it. Thank you in advance