Open the Settings app on your iPhone
Tap Cellular
Tap Wi-Fi Calling
Toggle Wi-Fi Calling on this iPhone to the On position
If prompted, review the E911 address and update it if needed
Tap Save
Wait for Wi‑Fi Calling to activate
Confirm it’s enabled by checking for “Wi‑Fi Calling” in Cellular settings or the carrier indicator on the status bar
Make a test call using Wi‑Fi to verify it works