Hi!
The hallmarks of the Facebook Events plugin (you must also have installed and activated The Events Calendar) are a new Facebook settings tab (Events → Settings → Facebook) and a new menu option labelled Import: Facebook which appears under the main Events menu in the admin environment.
Are you seeing those? You might also get a good sense of what to look for by reviewing the new user primer:
https://theeventscalendar.com/support/documentation/facebook-importer-new-user-primer/
Let me know how you get on/if you have further concerns 🙂