Only allow login from specified google app domain

Hey everyone!

Right now anyone with a google account can sign in to my wordpress site. How do I limit to only a specific domain?

I have changed Authentication type in google app engine to “Google Apps domain” and specified the domain, but regular gmail accounts can still sign in.

I have searched around but not found any solutions.

https://www.ads-software.com/plugins/nextend-google-connect/