How do I deactivate an export? What does this mean?

In your selected Inkspace, go to the "Exports" tab and select "Settings" for a particular export.

Toggle "Active", which will deactivate your export – it won't be possible to download it. Deactivation becomes effective immediately. An export that's been deactivated maintains all its settings. It still takes up a slot in your subscription plan; the slot is available again only after the export is removed.

If you click on the link shared with your publisher, you will see Error 404.