Unable to update and activate IPhone help!!

Hi! So my brother restarted his phone and then after that this popped up saying it was Unable to activate it because an update is required.

So i use my computer to go on itunes and I connect his iPhone then I did the steps to click on an IPhone icon and just click update but instead as you can see in 2nd picture that popped up. His SIM card is in there correctly we even took it out and put it back in nothing worked I don’t know what to do. Please help!!!