How to add multiple values to an object ID later in mongodb

I am trying to add values inside the object id. Object id is created before but I want to add more values in the future inside the object ID.

This is my MongoDB database:

[{
        label: 'colors',
        options: [
            { label: 'Black', value: 1 },
            { label: 'Green', value: 2 },
        ]
    }]

My expectation is when I will send a new object it will insert a new object inside the options property. suppose my new object is {label: ‘blue’, value: 3} it will be like this:

[{
        label: 'colors',
        object: [
            { label: 'Black', value: 1 },
            { label: 'Green', value: 2 },
            {label: 'blue', value: 3} 
        ]
    },

I am trying this way, I am storing the previous data value, inserting a new value, and sending it to the backend. but it’s not working. is there any different way I can fix it?

  const addAttributeValues = (e: React.FormEvent<HTMLFormElement>) => {
        e.preventDefault()

        if (label === '') {
            return
        }

        const slug = label?.split(' ').join('-')
        const options: any = [] // previous value storing 
        let update; // inserting previous and new value

        if (attr.options) {    // checking if the previous data has options property or not
            options.push(attr.options)
            const length: any = options.length
            update = { options: { ...options, [length]: { label, slug } }, id: attr._id }
        }

        else {     // if option property doesn't exist it means no new value added before 
            update = { options: { label, slug }, id: attr._id }
        }


        fetch('http://localhost:5000/dashboard/attributes', {
            method: 'PUT',
            headers: { 'content-type': 'application/json' },
            body: JSON.stringify(update)
        })
            .then(res => res.json())
            .then(data => {
                setLabel('')
                setIfShouldUpdate(true)
            })

    }

Backend API, I use put method, I don’t know is there any other method for inserting new values in the future.

 // ADD ATTRIBUTES VALUE
        app.put('/dashboard/attributes/', async (req, res) => {
            const { options, id } = req.body
        
            const filter = { _id: objectId(id) }
    
            const updateDoc = {
                $set: {
                    options: options
                },
            };

            const result = await unityMartAttributes.updateOne(filter, updateDoc);
            res.json(result)
            console.log(result);
        })