I uploaded a test html5 game just see how it works on mobile but I can't get it to run in fullscreen in portrait on my iphone. I chose "click to launch in fullscreen" and checked mobile friendly. Now when I hit the play button the game on Safari on iOS the game starts but the UI of Safari is still visible. If I go in landscape und swipe up it is fullscreen but when I rotate back to portrait the UI is there again. What should I do to have it in fullscreen without the Safari UI in portrait mode?

(I'm not sure if I can provide the link to the game because it's not my project. It's just an example project that came with the development tool.)