How do I save a photo or video from my Instagram story to my phone's camera roll?
Before you share a photo or video to your story, you can tap 
at the top of the screen to save it to your phone. You can also save a photo or video you've already shared:
Instagram app for Android and iPhone
- Open your story.
- Tap
(iPhone) or
(Android) in the bottom right of the photo or video you'd like to save.
- Tap Save (iPhone) or Save Photo/Video (Android).
- (iPhone only) Tap Save Photo/Video to save the individual photo or video or tap Save Story to save everything from your story as a single video.
Instagram Lite app
- Open your story.
- Tap
in the bottom right of the photo or video you'd like to save.
- Tap Save to Gallery.