Hello,
If you try to update the iOS on your device, you might see one of these messages:
"Unable to Check for Update. An error occurred checking for a software update."
"Unable to Verify Update. iOS failed verification because you are no longer connected to the Internet."
Try updating your device again using the same network. If you still see one of these messages, try updating your device using another network or update your device with iTunes. If the issue happens again after trying to update with multiple networks, remove the update.
Learn more about iOS updates.
Here's more info:
Get help with over-the-air iOS updates - Apple Support