Each of your topics or articles have Accessibility settings available to toggle on or off. These can be located by navigating to Admin -> Knowledge, selecting Topics or Articles and clicking on it's title to be taken into it's own settings area.
From here, you can navigate to the Settings tab, at the bottom of this page you will see a section titled 'Accessibility'. Selecting 'Edit Accessibility' will allow you to modify the options available as desired.
Options include:
Section Headers - here you can toggle between the below options:
Hide section headers in all modules in this topic.
Show section headers in all modules in this topic (can assist keyboard navigation and screen readers).
Narration Transcripts - here you can toggle between the below options
Hide narration transcripts for all narrations in this topic.
Show narration transcripts for all narrations in this topic (required for WAG 2.1 Level AA Accessibility standards).