Make sure your device has added the latest software version. Follow the steps below:
1. Open your iPhone, then go to Settings => Phone and activate Wifi Calling .
2. Add Wifi Calling on other devices.
3. On your other devices, login to iCloud and FaceTime using the same Apple ID and password that you use on your iPhone device.
4. Activate Wifi Calling:
5. Now on the screen of other devices appears a 6-digit code, your task is to enter this code into your iPhone and click Allow.
On Apple Watch, Wifi Calling will open when Calls on Other Devices is activated.
If you can't add the device, check the following items:
- On iPhone phones, make sure Wifi Calling and Allow Calls on Other Devices are activated, and your device appears under Allow Calls On.
- Make sure you are using the same Apple ID account for FaceTime and iCloud on your iPhone device and on other devices.
- Remove device:
If you don't want to use Wifi Calling from another device, you can delete it:
To turn off Wifi Calling on Apple Watch, you access Apple Watch on your iPhone phone, click Phone => Wifi Calls .
If you can't activate or use Wifi Calling, make sure your carrier supports Wifi Calling, and your device has the latest software version installed.
Follow the steps below if you cannot open Wifi Calling or you cannot make Wifi Calling calls.
Note: after each wait for about 2 minutes before taking the next steps.
Note :
FaceTime is not available for all countries and regions.
If your Mac device doesn't have FaceTime, you can download the application to your computer and install it here.
Good luck!