It may take some time to get used to how your iPhone will function once you stop your side button from ending calls, so here are some things you can expect.
Going forward, if you press the side button when you get an incoming call notification, the call will be silenced (not ended) and your screen locked. As usual, you can tap Decline to reject an incoming call, or if you need a hands-free option, activate your Siri and ask it to hang up the call.
The side button won’t end a call in progress, but your screen will still be locked. If you want to end a current call, you’ll have to tap the red “End Call” button on your screen — it’s the round button with a telephone facing down. If you have left the phone or your FaceTime session during your call, tap the green icon around the time display at the top of the screen to return to it, then end the call.
