I'm trying add Instagram login button to my project but I can not find any documentation talking about that, Why?
I'm trying add Instagram login button to my project but I can not find any documentation talking about that, Why?
Because such a thing does not really exist.
For the IG Basic Display API, the documentation explicitly says,
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.
https://developers.facebook.com/docs/instagram-basic-display-api
And outside of Basic Display API, for professional/business accounts:
App user authentication is handled through access tokens. Instagram Professional accounts are accessed indirectly through Facebook accounts, so all API requests must include your app users's Facebook User access token. You can get tokens from app users by implementing Facebook Login. Note that Facebook Login does not support Instagram credentials so app users must sign in using a Facebook account.
https://developers.facebook.com/docs/instagram-api/overview#authentication