You can add the camera app to the lock screen, for easy access in times or picture panic, but as with most phones nowadays there's no dedicated physical shutter button. (techradar.com)
The right - hand side of the phone is where you'll find all the physical buttons in the form of a volume rocker, power on / off switch and physical shutter button for the camera. (techradar.com)
The case is made out of shock - absorbing material to help your iPhone from the perils of the laws of physics, and the physical shutter button works with the default camera app. (businessinsider.com)