How do I save a live video to my phone's camera roll?
After you've ended a live video on Instagram, you can tap Save in the top right to save the video to your phone's camera roll. Keep in mind that only the video is saved, and not things like comments, likes and viewers.
You're only able to save a live video right after you've ended it. Only you will see the option to save your live video.
Note: It may take a minute for a live video to save to your phone, especially for longer videos.