Apple monthly charge $4.99 for facebook

There is no Apple fee for using Facebook. Facebook does have supporter subscription options that are $4.99 and would be billed through Apple if you subscribed through an app on an Apple Device. See: https://www.facebook.com/help/219372401985734/

To cancel a subscription that was billed through Apple, see: If you want to cancel a subscription from Apple - Apple Support

If you subscribe to something Facebook related you can cancel, see If you want to cancel a subscription from Apple - Apple Support