How
PowerPoint does not have “styles” for headings like other Microsoft products. Instead, headings are implemented via slide titles and section names.
The following article from Microsoft describes several methods for titling slides in PowerPoint: Title a slide.
The following article from Microsoft describes how to break a presentation into “sections” and give each a unique name: Organize your PowerPoint slide into sections.
Verify
To verify that all slides in a PowerPoint presentation have titles, you can use the Accessibility Checker.
If all slides have titles, you will see a checkmark next to “Missing slide title.” You should also ensure there is a checkmark next to “Duplicate slide title”.
If all sections in the presentation have a name, you will see a checkmark next to “Default section name.” You should also ensure there is a checkmark next to “Duplicate section name.”