I have 2 models: Room and Category

this is Room Model

import mongoose from "mongoose"

const roomSchema = new mongoose.Schema({
    name: {
        type: String,
        require: true
    },
    slug: {
        type: String,
        lowercase: true
    },
    image: {
        type: String,
        require: true
    },
    category: [{
        type: mongoose.Schema.Types.ObjectId,
        require: true,
        ref: 'Category'
    }],
    product: [{
        type: mongoose.Schema.Types.ObjectId,
        require: true,
        ref: 'Product'
    }]
},
    {
        timestamp: true
    }
)

export default mongoose.models.Room || mongoose.model('Room', roomSchema)

this is Category Model

import mongoose from "mongoose"

const categorySchema = new mongoose.Schema({
    name: {
        type: String,
        require: true
    },
    slug: {
        type: String,
        lowercase: true
    },
    image: {
        type: String,
        require: true
    },
    product: [{
        type: mongoose.Schema.Types.ObjectId,
        require: true,
        ref: 'Product'
    }],
    room: {
        type: mongoose.Schema.Types.ObjectId,
        require: true,
        ref: 'Room'
    },
},
    {
        timestamp: true
    }
)

export default mongoose.models.Category || mongoose.model('Category', categorySchema)

I’m making an api route to get category detail and api route look like this

import { connect } from '@/backend/config/mongodb'
import { NextResponse } from "next/server"
import Category from '@/backend/models/Category'
import Room from '@/backend/models/Room'

connect()

export async function GET(req, { params }) {
    try {
        const { id } = params
        const category = await Category.findById(id).populate({
            path: 'room',
            model: Room
        })
        console.log('???? ~ GET ~ category:', category)
        console.log('???? ~ GET ~ category.room:', category.room)
        if (!category) {
            return NextResponse.json(
                { error: "Category not found!" },
                { status: 404 }
            )
        }
        return NextResponse.json({
            success: true,
            category
        })

    } catch (e) {
        console.log(e)
        return NextResponse.json({
            success: false,
            message: "Đã xảy ra lỗi xảy ra! Vui lòng thử lại sau"
        })
    }
}

**When I log category which I populate Room model is undefined.
This is log that I showned

~ GET ~ category: { _id: new ObjectId(‘6630f8cc193d4c59d6ee36ec’), name: ‘test 2’, slug: ‘test-2’, image: ‘https://res.cloudinary.com/dq7vzcw0s/image/upload/v1714485449/nhaxinh/categories/1714485448557.jpg’, product: [], __v: 0 } ???? ~ GET ~ category.room: undefined

Please, help me find me the error**