How do I know I’m calling with wifi

From the support document you posted from: "If Wi-Fi Calling is available, you’ll see Wi-Fi after your carrier name in the status bar. Then your calls will use Wi-Fi Calling."

If the Wi-Fi label is not visible, try turning on Airplane mode for a a few seconds and turn on Wi-Fi. If available it should then show your carrier's name and the Wi-Fi label. If this is visible all calls placed will use Wi-Fi calling.

If the label does not show up, then Wi-Fi calling is not available.

Swipe down from the top right corner to open Control Center. Carrier Name should then appear there with the rest of the icons and the Wi-Fi label. It should work the same with AT&T.

michelefromwaldron wrote:

but is it perhaps different for AT&T

It is not.

As Phil0124 says:

Thanks Sberman. 😉