In a FaceTime call, you can collaborate on a shared document. You can initiate collaboration in a FaceTime call that’s in progress, or you can initiate collaboration from the app where the document was created.
Start a conversation in the FaceTime app , tap the screen to open the FaceTime controls.
Open the document, then do one of the following:
Tap Collaborate in the notification that appears.
Tap Share your screen in a FaceTime call on iPad