When you export a single page, the headings will be numbered the same as on your Confluence page.
When you export a document with multiple pages, the numbering will continue across these pages. You can export these pages by navigating to Space operations and the Export pdf.
If you use the Scroll Exporter app by K15T, Scroll Exporter will take control of the numbering. This behavior is implemented in consultation with K15t.
You can include numbering in the Scroll Exporter by using a template that supports numbering. One of the default templates that supports numbering is titled Documentation.
For more information about numbering your documents when you use Scroll Exporter, please turn to the K15t documentation.
Not sure if you are using the default Confluence exporter or the Scroll Exporter? If you don't see an icon next to the Export menu item, you are most likely using the Confluence export.