My tags of type Mongoose.Schema.ObjectId is not getting updated.

When I try to give the id of the tag , it is still showing empty in the postman .create bookmark post route.​Here is how my model and controller looksconst mongoose = require('mongoose');//bookmark modelconst bookmarkSchema = mongoose.Schema(  {link: {type: String,required: [true, 'Bookmark URL or Link is required'],unique: true,    },title: String,createdAt: Number,updatedAt: Number,Publisher: String,tags: [      {type: mongoose.Schema.ObjectId,ref: 'Tag',      },    ],  },  {    // Make Mongoose use Unix time (seconds since Jan 1, 1970)timestamps: { currentTime: () => Math.floor(Date.now() / 1000) },  });const Bookmark = mongoose.model('Bookmark', bookmarkSchema);module.exports = Bookmark;//tag modelconst mongoose = require('mongoose');const tagSchema = mongoose.Schema(  {title: {type: String,unique: true,},createdAt: Number,updatedAt: Number,  },  {// Make Mongoose use Unix time (seconds since Jan 1, 1970)timestamps: { currentTime: () => Math.floor(Date.now() / 1000) },  });const Tag = mongoose.model('Tag', tagSchema);module.exports = Tag;Bookmark controller jsexports.createBookmark = async (req, res) => {  const { link } = req.body;  try {    const newBookmark = await Bookmark.create({      link,    });    res.status(201).json({ data: newBookmark, status: 'successfull' });  } catch (err) {    console.log(err);    res.status(400).json({ error: err, status: 'fail' });  }};

Submitted August 31, 2020 at 04:37AM by DVGY