The instructions apply to the Instagram app for iOS and Android.
Alternatively, you might record your screen or use an app like Repost.
Could you be liable for copyright issues?

TapAdd reel to your story.
Go back to the Home tab and tapYour Story.
TapNewor choose an album to add it to.

punch in a name for the highlight and tapAdd.
On your profile, your highlights appear above your posts.
Tap the highlight with the video to view it.

Just ensure to give credit to the original creator.
The steps forrecording your screen on Androidandrecording an iPhone screenare different.
Here’s how:
In the Instagram app, tap thethree dotsin the upper-right corner of the video.

TapLinkto copy the video link.
Download theRepost for Instagram app.
Once it’s downloaded, tap the icon to open it.
The app should automatically detect the link you copied.
You might have to wait a few seconds.
Tap thevideo thumbnailwhen it appears in the app.
TapAllowIf prompted to give access to your gadget media.
The video will open in the Instagram app.
Add a caption or anything else you want to include and tapShare.
The video will appear as an original post on your profile.