This setting allows you to hide the default navigation bar login buttons for external authentication.

If you have social logins and your own login pages using this method Customizing login and other account ui MVC, then you will probably want to hide the default social login buttons.

Settings Relevant to Organizations That Want to Provide a Single Sign-on Experience

• HideExternalLogin - as described above.
• HidePasswordLogin - as described here Hide Password login
• AllowUserToChooseSocialLoginEmail - when registering the local account for the first-time log-in, should the email used be editable or taken from the external userid?
• SkipExternalAccountConfirmationScreen - the screen where the local account is confirmed for the first time may be skipped.
• OpenIDConnectScope - the normal "openid profile" is used if you do not provide your own. Consider adding "email" to the list if available at the IDP.

See: TurnkeySettings