If your iPhone won't turn off the usual way, you can force restart it with a button combination specific to your iPhone model.
If your iPhone is showing a black screen that never goes away, you should try resetting it or putting it into recovery mode.
Unlike a regular restart, a force reboot is often the first port of call for resolving software issues impacting your iPhone 16e – like if the device is frozen, for example. If your iPhone isn't ...