Press and hold the side button and either volume button, then release if the Emergency SOS screen appears
Tap Cancel on the Emergency SOS screen
If your iPhone is stuck on SOS mode because there is no cellular service, move to an area with better signal
Turn Airplane Mode on, then turn it off
Restart your iPhone
Remove and reinsert the SIM card if your iPhone uses one
Go to Settings
Tap Cellular
Turn Cellular Data on
Tap Network Selection
Turn Automatic on
Update your iPhone to the latest iOS version
Contact your carrier if SOS mode continues to appear