Cannot send one var as string while sending file

[Snakzi]

I'm using my form to send data, mostly strings and also a file.

data() {
    return {
        form: new Form({
            serverid: '',
            name: '',
            ipaddress: '',
            port: '',
            description: '',
            servertype: '',
            slots: '',
            discord: '',
            facebook: '',
            twitter: '',
            coverimg: null,
        }),
        coverImgUrl: '',
        remember: false
    }
}

async addServer () {
    await this.form.submit('post', '/server/add', {
        transformRequest: [function (data, headers) {
            return objectToFormData(data)
        }]
    })
    .then(({ data }) => {
        this.$router.push('/' + data.serverid)
    })
    .catch(({ error }) => {
        //Leave Empty
    })
}

However, I'm not able to send a file and convert "description" to a string using JSON.stringify. How am I going to approach this with vform?