If you are creating a new Instagram account for authentication, we recommend you stop where you are. Facebook announced about a year ago that they will be deprecating Instagram authentication and want everyone to use Facebook authentication only (since Facebook owns both).
While Instagram authentication does still work, it's possible they are disallowing it with new apps and/or may disable authentication completely in the future.
We are keeping the Instagram plugin available for backward compatibility with sites that have enable Instagram authentication in the past and for additional features available in the Instagram plugin, but we do not recommend using it for setting up authentication on new sites.
I hope that helps explain, but if you need anything else, just let us know.
Thanks,
Alex
Facebook and instagram login
