Easiest way to unarchive a story on instagram?

if the story you want isn't in there at all, archiving was probably switched off when you posted it. it's under settings > archiving and downloading, save story to archive. it only saves from when you turn it on, so older ones are gone unless they're in a highlight.

profile > the three lines top right > Archive. make sure it's on Stories archive (switch at the top if it opens on posts). there's no button that puts an old story back up as if nothing happened. open it and you can share it to your story again, add it to a highlight, or share it as a post. resharing counts as a new story so it runs another 24 hours.