You're welcome.
If you use data to make a FaceTime call you can check how much has been used in your iPhones settings too.
"Step 1: Launch the FaceTime app.
Step 2: For the FaceTime call you want to track, tap the small “i” icon, as seen on the left screenshot above.
Step 3: This will take you to the Contact and call details. Right at the top, you can see whether it was an incoming or outgoing call, the duration of the call, as well as the amount of data used for that call. In the example above, you can tell that my two minute FaceTime call used 8 MB of data."
Or
"Launch the Phone app on your iPhone (or iPad with cellular built-in).
Tap on Recents in the bottom navigation.
Tap on the Info button to the right of the FaceTime audio or video call you'd like to see data usage for.
The data usage will show underneath each FaceTime call at the top."
Current Phone >
Samsung Galaxy s²⁴ Ultra 512gb.