Once you have opened a chapter from My Activities, click on the right arrow to move pages. On some pages, the text may instruct you to click on boxes to reveal more content. Click on anything the page instructs you to once everything on the page has loaded.
If you want to skip back to an earlier page, click the three horizontal lines icon in the top left of the page to bring up the Menu.
When you are finished with a chapter, click the X icon in the top right of the screen to close it, you can revisit it at any time. .