At the bottom of the screen in the Quests (no need to scroll the page down), there should be three buttons to select - 'Select Episode', 'Confirm Allies' & 'Back'.
Select 'Select Episode' & it will give you a list of Episodes from 1 to 10. At the bottom of the screen again, there should be a button called 'Next Page' that allows you to progress to the Episode 11 and onwards.