From the Home screen, navigate: Settings > Phone.
If using an eSIM with a second line, select a line (e.g., Primary, Secondary, 888-888-8888, etc.) then proceed to step 2.
Tap Wi-Fi calling.
Tap Update Emergency Address.
This info gets transmitted to the emergency dispatcher for all 911 calls made over a Wi-Fi network. If address validation fails then you are prompted to enter a new address until a valid address is entered.
To proceed, from the Terms and Conditions screen, tap the radio button then tap Continue.
Do one of the following to return to the Home screen:
Press the Home button (for iPhone 8 and and previous models).
Swipe up from the bottom of the screen (iPhone X / XS / XS Max / XR).