You can tag your followers or people you're following in your photo or video posts.
To tag someone, tap Tag People on the same screen where you add captions and location.
Then tap on the name of the person you want to tag in your post.
The person will receive a notification that they've been tagged in your photo. If your posts are public, anyone can see the post and who you tagged. If your posts are private, only your followers will see your post and the tags.