Open Instagram and create a new post, story, reel, or comment
Tap Tag People on a post before sharing
Tap the photo or video where you want to add the tag
Search for your friend’s username
Select the correct account from the list
Tap Done or Save
For Stories, use the Mention sticker or type @username
For captions or comments, type @ followed by the person’s username
Make sure the account is public or allows tagging if the tag does not work
Edit the post later and tap Edit to add or change tags if needed