registration does not work
1. In JFBConnect > Configuration > General, I turned on the "Integrate Into Joomla Login" option and navigated to your front-end Joomla users component login page
staging1.besthalalholiday.com/en/index.p...com_users&view=login then clicked the Facebook button. A user was successfully created and logged in properly. I then disabled that option again and deleted the user to clean up and try #2.
2. I then used the SCLogin module Log in button found at
staging1.besthalalholiday.com/en/ - When the modal was launched, I clicked the Facebook button and, once again the user was successfully created and logged in properly. I have not deleted the user and you can see the correct mapping in JFBConnect > User Map area that it is linked to my test FB account.
You will need to provide more detailed steps on how to reproduce what you are seeing with the registration failing. I am able to successfully register and log in via a Facebook user on your site.
-Melissa