IOS 15.5 unable to update

i get this error when I try to update my IOS software to 15.5. I have reset my network settings, no help. I have tried 3 different wifi networks, no help. I have turned my iPhone off and on 3 times, no help. I have tried with VPN off, no difference. I have deleted the update and reinstalled it 3 times, no help. I have tried installing with and without the phone plugged into an original iPhone charger, no help. What else should I try?