Scroll down and select Phone.
Find Wi-Fi Calling and turn it on.
You might need to enter or confirm your address for emergency services.
If Wi-Fi Calling is available, you’ll see “Wi-Fi” in the status bar when viewing Control Center.
Remember that when cellular service is available, your device will use it for emergency calls.
However, if you turn on Wi-Fi Calling and cellular service isn’t available, emergency calls might use Wi-Fi calling. Your device’s location may be used to aid response efforts when you place an emergency call, regardless of whether you enable Location Services.
Tap the More option (usually represented by three dots or lines).
Navigate to Settings.
Look for Wi-Fi Calling and enable it.