Social signup links for custom developed signup page


I am looking for a documentation to develop custom signup page with access to social connections. I see example for custom signup for database signup but no documentation is available to link social connection signup.

There is example in lock page for login for both database and social logins. No example or api found for social connection signup. Any idea on how to integrate the social connection signup with custom developed signup page. I am looking same like the buttons placed on auth0 lock page but they need to be aligned differently with the our app fonts, colors, styles,…