Hi @parkdad
I am not that familiar with Flutter, but if you mean WebView application, then most of the providers work there, except Google, that doesn’t allow using their OAuth endpoints over WebView, so for that reason we hide the Google button in WebView as it couldn’t work anyways. ( Note: There are some exceptions like the WebView of Facebook, Instagram and Twitter so there our social buttons will also appear. )
However if you would like to use social login within your application itself, then you will need to do some custom coding to handle both the registration and the login.
If you are interested in it, then here you can find our documentation where you can see how you can use our REST API, and what you can do with it: https://nextendweb.com/nextend-social-login-docs/nextend-social-login-rest-api/
Please note that we can not provide support for custom coding!
Best regards,
Laszlo.
