My website is toeic990.vn , some member cant log in because that error, please help me.
Hi Hoang,
That sounds like something that needs to be fixed in your app’s settings on developer.facebook.com.
Once you’re logged in there and editing your app, it should be under Products >> Facebook Login (in the left-hand menu). In there, you can add your domain(s) to the “Valid OAuth Redirect URIs” section.
Loz