If the screen resolution of your mobile device is sufficient, first connect to a WiFi network. Also, your browser needs to be able to play videos with overlays. Older mobile browsers usually don't support this option.
Play in mobile browser Android 4 and higher.
Play in Edge on Windows 10 Mobile.
Play on iOS 10 and higher. When watching the documentary on fullscreen, please do click on the resize button at the lower right hand side of the player.
The video should be able to play with overlays in Safari. With fingers crossed, that is.