If your Facebook app has been disabled for login starting from January 2024, it's likely you had not associated it with a verified business.
Indeed 'Advanced Access' for Facebook applications now requires Business Verification.
An app that must perform a Facebook login requires advanced level access to permissions to retrieve email address and profile informations, so you must complete Business Verification in order to activate it.
See this blog post for more information: https://developers.facebook.com/docs/development/release/business-verification?locale=en_US
Once you have completed the business verification for your company, you will see it confirmed under the section 'App settings' -> 'Basic' -> 'Company verification':
To confirm that the advanced access for your app has been enabled, open the 'Permission and Features' settings and verify that 'email' and 'public_profile' have been granted: