How to restart an iPhone

Press volume up - release and quickly press volume down, then release and hold power button untill you see an apple logo then release the power.

Hello ~ Sorry you are having an issue. Give this a try by clicking on and following the instructions there…

If your iPhone won't turn on or is frozen - Apple Support

If you need further assistance after you try that post back and we will co working on it. Take care.

~Katana-San~

See if this helps: If your iPhone won't turn on or is frozen – Apple Support (UK)