Cannot read properties of undefined (reading ‘push’) in node js

i’m trying to add roomSchema to a userSchema

this is my code

router.post('/join-room', async (req, res) => {
  const { roomId, userId } = req.body;
  try {
    const user = await User.findById(userId);
    const room = await Room.findById(roomId);
    if (!user || !room) {
      return res.status(404).json({ message: 'User or room not found' });
    }
    user.rooms.push(roomId);
    await user.save();
    res.json({ message: 'User joined room successfully' });
  } catch (error) {
    console.error(error);
  }
});

this is my json

{
  _id: new ObjectId("6436c40c989d571ad31563a8"),
  name: 'jquery',
  email: '[email protected]',
  password: '$2a$10$fdPk3EzPPZc4SDxGmYnj3usFm9IlU0SNb.Ek4hINXHTfNSAclscxW',
  __v: 0
} {
  _id: new ObjectId("6436bf25f70ece2db5576081"),
  created_date: 2023-04-12T14:24:37.439Z,
  name: 'vue',
  __v: 0
}

this my error

 Cannot read properties of undefined (reading 'push')

please how can i go about this