HOW TO ACCEPT COLLABORATION INVITES ON INSTAGRAM
1. You'll get a notification that you've been invited to be a collaborator on a post. It will show up within your messages.
2. The next screen will show you the post for you to review. After viewing click the 'Review' button.
3. A pop up will give you the option to accept or decline the invitation. If you accept, then then post will also be shared on your feed for your followers to view. Your profile name will also feature on the original post on the inviter's feed.
4. As in the image, the post will showcase both of your profile names. Any comments and likes will be shown across both user profiles.