Hi,
Most of my colleagues are using windows and android, and they don't have problem using FB login, except this one who is using iphone and mac pro, and he can not login by FB on both his cell phone and mac.
Following is the error message:
Can't Load URL: The domain of this URL isn't included in the app's domains. To be able to load this URL, add all domains and subdomains of your app to the App Domains field in your app settings.

Could you tell how to fix the problem?

Best regards

It doesn't seem something related to the iphone/mac but rather to the domains set in the FB app. Maybe iphone/mac uses a different domain to login.
Try to investigate on it and add additional domains to the FB app configuration.

Best regards