Commented code solved Uncaught (in promise) Timeout

captchaVerification.js

async function captchaVerification() {
    return await new Promise((resolve, reject) => {
        const captcha = document.createElement('div')
        captcha.setAttribute('id', 'g-recaptcha')
        document.getElementById('main').appendChild(captcha)
        const verifyCallback = async (response) => {
            if (response) {
                const data = {
                    token: response,
                }
                /* const verifyStatus = await fetch('app', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    redirect: 'manual',
                    body: JSON.stringify(data)
                })
                if(verifyStatus) {
                    captcha.remove()
                    return resolve(true) 
                }
                else return reject('Invalid captcha verification.') */ 
                return resolve(data) // We need to resolve promise anyway
            } else {
                grecaptcha.reset()
                return reject('Invalid captcha verification.')
            }
        }
        grecaptcha.render('g-recaptcha', {
            'sitekey': '6LdFlOQUAAAAABdYGtt_xTVH4hj57fvCrRTgZcST',
            'theme': 'dark',
            'callback': verifyCallback
        })
    })
}