By default most browsers such as Google Chrome, Firefox, Internet Explorer and Safari block pop-ups. So, if your browser is blocking the Facebook pop-up you need to disable the pop-up blocker.
How you turn off the pop-up blocker differs per browser, whether you’re on Window, Mac or a mobile phone.
You’ll find instructions for most browsers here
This article describes how to disable pop-up blockers on your Mac:
This article describes how to disable pop-up blockers for Safari on Mac and iPhones and iPadshttps://www.lifewire.com/manage-pop-up-blocker-in-safari-4136249
This article describes how to disable pop-up blockers for Android