Why can't my Mac make phone calls?

My iPhone is not currently allowing calls using this Mac. I’d like help to troubleshoot and enable this feature. **iPhone Settings** > **Cellular** > **Allow Calls on Other Devices** is off. I tried to turn it on: >Cannot Turn On Calls on Other Devices — FaceTime and iCloud must be signed in to the same Apple ID to enable Calls on Other Devices. **iPhone Settings** > **FaceTime** is on. iPhone/Settings/General/About I opened FaceTime on my Mac, **Settings** > **Calls from phone** is checked. What might I be missing?