With the iPhone X, not only has the home button disappeared, the restart has also changed. You can read here how to restart the mobile phone..
If your iPhone X has hung up or is running very slowly, a forced restart or soft reset can help. Since the newer iPhone models of the X series do not have a home button, the tried and tested soft reset method has been changed. You can read how you can force a restart in our tips + tricks.
Either your iPhone still reacts and you can restart it by switching off the device, or the device no longer reacts at all and you have to force a restart. We cover both cases below.
1st step:
If your device is still responding, press and hold the side button on the right and the volume down or volume up button on the left of the iPhone X until the " Power off" slider appears..
2nd step:
Move the Power Off slider to the right to turn off iPhone completely. If the device no longer reacts, you can force a restart. First press the volume up key and release it again. Then press the volume down button and release it again . Then press the right side button and hold it down until the Apple logo appears. Your smartphone will now restart. If the " Power off " slider has appeared and the mobile phone has been shut down in this way, press the right side button on the iPhone until the Apple logo appears and the device restarts.