How to use 2 sets of AirPods while FaceTiming on an iPhone in 2024?
How to use 2 sets of AirPods while FaceTiming instead of listening music or watching movies on an iPhone?
iPhone 15 Pro, iOS 17
Presumably “2 sets of AirPods while FaceTiming” means that each of two people on a FaceTime call is using her/his own set of AirPods paired to an iPhone or iPad that is participating in FaceTime with that person’s Apple ID.
See this from the iPhone User Guide.
Change FaceTime audio settings on iPhone - Apple Support