:) how to put iPhone/iPad in DFU mode?
for iPhone 8/X/XR/XS:
1.Plug your iPhone X or iPhone 8 into your Mac or PC.
2.Make sure iTunes is running.
3.Turn Off your iPhone X or iPhone 8 (if it isn't already).
4.Press and hold down the On/Off button on the right side of your iPhone for 3 seconds...