How do I share a live video to Instagram Stories after it's ended?
Once your live video ends, you can share a replay of it. Like other photos and videos you share to stories, live video replays disappear from Feed and your profile after 24 hours, unless you add those stories as highlights.
To share a replay of your live video, tap Share at the bottom of the screen after you've ended your live video. To discard your live video, tap 
then select Discard. You can also tap Save in the top right to save it to your camera roll.
Live video replays include all the likes and comments from your original live video. The number of viewers for your live video includes everyone who watched the live video and the replay.
Learn more about where your story appears and who can see it.