YTPlyaer YouTube full-screen display is not available

Question

I have embedded a YouTube player using YTPlyaer ver 3.2.9

On desktop and android devices everything works perfectly fine, On IOS the firescreen button is missing

This is the init code im using:

    var video_source = "https://www.youtube.com/embed/somecode";

    this.youtube_player_element.YTPlayer({
        containment: 'self',
        videoURL:video_source,
        ratio:'4/3',
        optimizeDisplay: true,
        showYTLogo: false,
        addRaster: false,
        showAnnotations: false,

    });