This article explains whether it is possible to hide the Social Connections buttons on the Universal Login page. 

• Social Connections

When social connections are enabled, a button is added to Universal Login. However, if the user is redirected to the social identity provider directly, there is often a need to hide the social login button.

There is currently no way to hide social connections if they are enabled against applications. Please submit feedback to recommend this feature to the Auth0 Product teams. 

There is a workaround if a custom domain is present:

• Use page templates and JavaScript to hide the button, as the HTML template is customizable.
• Please note that this approach is not recommended, as the page's structure could change, potentially breaking any JavaScript-based customizations that may have been put in place. See the warning under CSS customization for more details.

See example below, please note that this is not a complete solution but an idea to build on:

...
<script>
    let xpathExpression = `//button[span[text()="Continue with ABC"]]`;;
    let socialButton = document.evaluate(xpathExpression, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
    socialButton.remove()
  </script>
  </body>
</html>