Facebook is very clear about this. According to their official Help Center:
Can You Actually See Who Views Your Facebook Profile? The Truth Behind the Myth how to find profile viewer in facebook
Facebook protects this data for privacy reasons. If users knew their every click was being tracked and reported, they would spend less time on the platform. To keep people browsing freely, Facebook keeps "viewing" data strictly confidential. Beware of "Profile Viewer" Apps and Scams Facebook is very clear about this
While you can't see "silent viewers," you can see who interacts with your content. If you want to know who is paying attention to you, look here: how to find profile viewer in facebook
A popular workaround involves looking at the "View Page Source" of your Facebook profile and searching for a list called InitialChatFriendsList .