index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Chromium Metrostroi</title>
    <style>
        body {
            background-color: rgb(38, 38, 38);
            background-image: url("");
            background-repeat: no-repeat;
            background-size: cover;
            height: 100vh;
            margin: 0;
        }
    </style>
</head>
<body>
<script>
    const image_urls = ["https://steamuserimages-a.akamaihd.net/ugc/1740099129541706537/C03609B585C140DD71FCDE35E8989989BC9732CC/?imw=512&amp;imh=288&amp;ima=fit&amp;impolicy=Letterbox&amp;imcolor=%23000000&amp;letterbox=true",
                        "https://i.ytimg.com/vi/eg99NX3LMUA/maxresdefault.jpg"];
    
    let currentImageIndex = 0;
    let body = document.getElementsByTagName('body')[0];
    function changeBackgroundImage() {
        currentImageIndex = (currentImageIndex + 1) % image_urls.length;
        body.style.backgroundImage = 'url(' + image_urls[currentImageIndex]; + ')';
        console.log(image_urls[currentImageIndex]);
    }

    // Таймер смены раз в 5 сек
    setInterval(changeBackgroundImage, 3000);
</script>
</body>
</html>