is turning off my flashlight still possible?

Or just ask. "hey siri turn off the flashlight" works even with the phone locked, same with google assistant on android.

iPhone or Android? On iPhone swipe down from the top right corner and tap the torch icon, or long press the one on the lock screen. Android it's the flashlight tile in quick settings. If the icon is greyed out, close the camera app. It holds the light while it's open.