The Instagram Basic Display API seemed as a possible solution, as it this API can return some users details. Unfortunately Facebook don’t want users use their Instagram account as a login option, as they stated:
Instagram Basic Display is not an authentication solution. Data returned by the API cannot be used to authenticate your app users or log them into your app. If you need an authentication solution we recommend using Facebook Login instead.
The main problem is that, this isn’t just a verbal warning since to be able to retrieve the user details your Instagram App needs the permission:
which is only available after an App Review, which will most likely fail because of the following reason:
We had plans on implementing Instagram as a new provider, however the deprecation of the Instagram API Platform was announced:
Some endpoints has already became deprecated:
and the “Basic” scope which would be required to read a user’s own profile info and media will also become deprecated in early 2020.
Currently we know no alternatives for the Instagram API, as it seems, some services will be offered directly by Facebook via the Instagram Graph API however it won’t be a direct replacement. This means, it can’t be used for the same purposes as the legacy Instagram API.