http
HTTP/1.1 200 OK
Content-Type: text/html
Permissions-Policy: fullscreen=(self)
<!DOCTYPE html>
<html>
<head><title>Video Platform</title></head>
<body>
<video id="player" controls></video>
<button id="fullscreen">Fullscreen</button>
<script>
document.getElementById('fullscreen').addEventListener('click', () => {
document.getElementById('player').requestFullscreen();
});
</script>
</body>
</html>