If your iPhone stuck on the apple logo during update, one of the easiest ways to fix this problem is '''forcing restart''' it. For iPhone 6S and earlier models, just press the "Home" button and "Sleep/Wake" button. Keep holding the buttons until you see the Apple logo. This will take about 10 seconds.
If the method mentioned above doesn’t work, you could also try to put your iPhone in '''DFU mode''' and restore it with iTunes. DFU will completely restore the device and erase all the data from your phone.
Source with more solutions: https://www.imyfone.com/iphone-issues/fix-iphone-stuck-on-apple-logo/