Partner applications can use the Socios.com login button to allow their users to log into their Socios.com account from a third-party environment.
Clicking on this button opens the Socios.com Connect login modal (such as any OAuth login system such as Google's, Facebook's, etc.) which in turn allows the third-party application to access Socios.com user data on the user's behalf.
Sample button
This example doesn't onboard all the OAuth mechanism, this is only a front-end example.
To fully implement it, you will need to dive into the rest of the Partner API documentation, notably the Authentication part.
Here is the official Socios.com login button:
And here is the needed CSS code to display it into a partner website: