Как сделать автоматический слайдер на JavaScript?

Question

AlinaMoskaluk @AlinaMoskaluk

Как сделать автоматический слайдер на JavaScript?

Есть готовый слайд . Но не знаю как доделать автоматическое переключение слайдов с интервалом в 2 секунды ? помогите..
HTML

<div class="slider-body">
        <h2>My first slider</h2>
        <div class="flex-wrapper">
            <div class="slider-wrapper">
                <div class="slide active">
                    <img src="img_1.jpg" alt="">
                </div>
                <div class="slide">
                    <img src="img_2.jpg" alt="">
                </div>
                <div class="slide">
                    <img src="img_3.jpg" alt="">
                </div>
                <div class="slide">
                    <img src="img_4.jpg" alt="">
                </div>
                <div id="btn-prev"></div>
                <div id="btn-next"></div>
            </div>
        </div>
        <div class="dots-wrapper">
            <span class="dot active"></span>
            <span class="dot"></span>
            <span class="dot"></span>
            <span class="dot"></span>
        </div>
    </div>

CSS

.slider-body {
    background-color: #73d58f;
    padding-top: 85px;
    padding-bottom: 140px;
}
h2 {
    text-align: center;
    font-weight: bold;
    font-size: 38px;
    line-height: 46px;
    color: #fff;
    margin: 0;
    margin-bottom: 80px;
}

.flex-wrapper {
    width: 100%;
    display: flex;
    justify-content: center;
}

.slider-wrapper {
    max-width: 800px;
    width: 100%;
    height: 490px;
    position: relative;
    box-shadow: 10px 10px 44px -10px rgba(0,0,0,0.75);
}

#btn-prev, #btn-next {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 50px;
    background-color: gray;
    opacity: 0.4;
    cursor: pointer;
    transition: opacity .2s ease-in-out;
}

#btn-prev:hover, #btn-next:hover {
    opacity: 0.6;
}


#btn-next {
    left: auto;
    right: 0;
}

.slide {
    width: 100%;
    height: 100%;
    display: none;
}

.slide.active {
    display: block;
}

img {
    width: 100%;
    height: 100%;
}

.dots-wrapper {
    display: flex;
    justify-content: center;
    margin-top: 15px;
}

.dot.active {
    background-color: #000000;
}

span {
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background-color: gray; 
    margin-right: 10px;
    cursor: pointer;
}
span:last-child{
    margin-right: 0;
}

JAVASCRIPT

const prev = document.getElementById('btn-prev'),
      next = document.getElementById('btn-next'),
      slides = document.querySelectorAll('.slide'),
      dots = document.querySelectorAll('.dot');

let index = 0;

const activeSlide = n => {
    for(slide of slides) {
        slide.classList.remove('active');
    }
    slides[n].classList.add('active');
}

const activeDot = n => {
    for(dot of dots) {
        dot.classList.remove('active');
    }
    dots[n].classList.add('active');
}

const prepareCurrentSlide = ind => {
    activeSlide(index);
    activeDot(index);
}

const nextSlide = () => {
    if(index == slides.length - 1) {
        index = 0;
        prepareCurrentSlide(index);
    }else {
        index++;
        prepareCurrentSlide(index);
    }
}

const prevSlide = () => {
    if(index == slides.length - 1) {
        index = 0;
        prepareCurrentSlide(index);
    }else {
        index++;
        prepareCurrentSlide(index);
    }
}

dots.forEach((item, indexDot)=> {
    item.addEventListener('click', () => {
        index = indexDot;
        prepareCurrentSlide(index);
    })
})

next.addEventListener('click', nextSlide);
prev.addEventListener('click', prevSlide);