The physical home button is no more, but there's a workaround you can use on pretty much any iPhone.

Quick Answer: To restart your iPhone without the power button, go to Settings > General > Shut Down, then slide to power off. You can also ask Siri to restart your iPhone without the button.

Take a Screenshot on iPhone by Tapping Its Back For even more convenience, you can use another iPhone accessibility shortcut to take screenshots without the buttons.