The shuffle button appears next to the download and share options if you go to the Series tab. It will simply start shuffling all the episodes from the selected season. However, this button is not available everywhere. For example, you can shuffle The Boys season 1 but cannot shuffle The Boys season 2.
During the play mode, you will also see the message saying that played episodes are shuffled.
The feature should be available on version 3.0.292.6357
Via: Android Police