The best way to do this is using Token authentication. With token authentication, your auth server will be informed about, and can approve or disapprove, every connection to your app, once every hour (by default -- you can set it to anything from 10 minutes to a day). You can send whatever data to your auth server you like as part of the token request, e.g. by setting it as an authHeader or authParam if using authUrl. Have a read of our token auth documentation or out token auth tutorial for more information.
(If you're on a Business or Enterprise packages, you can also talk to your support contact, who can help you with live debug information about your app's current connections).