To get full screen on Pluto TV or YouTube, tap the full-screen icon in the video player, it usually looks like a small square in the corner of the video. If it doesn’t work try rotating your device to landscape mode because some apps only switch to full screen when the screen is sideways. Also make sure you’re not using the browser’s “desktop mode,” since that can block full-screen playback on some phones and tablets. If you’re on a computer, just press F11 for browser full screen, or click the video’s own full-screen button.