index.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="styles.css">
    <title>My.PPS</title>
</head>

<body>
    <iframe id="iframe" src="https://www.bing.com/?toWww=1&redig=CFAD98CD42D94926AFAD6FFDDABDBFA7"
        style="height:100vh;width:100%"></iframe>

    <button id="open">Open Modal</button>

    <div id="modal" class="modal">

        <div class="modal-content">
            <span class="close">&times;</span>
            <img src="haha.png" width="100%;" height="100%">
        </div>

    </div>

    <script>
        var modal = document.getElementById("modal");

        var btn = document.getElementById("open");

        var span = document.getElementsByClassName("close")[0];

        btn.onclick = function () {
            modal.style.display = "block";
        }

        span.onclick = function () {
            modal.style.display = "none";
        }

        window.onclick = function (event) {
            if (event.target == modal) {
                modal.style.display = "none";
            }
        }
    </script>
</body>

</html>