While text is being read aloud, click on the back arrow to read the previous sentence or the forward arrow to read the next sentence. The Auto-Scroll setting is also accessible here while the play button is activated.
Click on expand to open the Reading Bar. When the Reading Bar is opened, it will be along the bottom of the page. You can still use the backwards/forwards buttons and toggle the Auto-Scroll here too. You can also follow along with a copy of the text being read if you have the CC (closed captions) Panel setting turned on, which it will be by default.
From the Reading Bar, you can see the progress bar here to see how far along you are with listening to the text. You can also click on this progress bar to navigate ahead or backwards in the audio.