URGENT 12.3.1 Verification Failure after Cellular update failure

if you have access to another phone, call apple support at 1-800-MY-IPHONE

or look at

https://support.apple.com/en-us/HT208733 which is what you should do after you see the "cellular update failed" notification. the gist is that you need to connect your phone to a computer with itunes and update it.

To deal with this known issue in which an iOS update from Apple makes cellular service on your phone inoperable , Apple requires you to send your phone off for repair... which can take up to six days... vs simply replacing the phone they broke. If you live close enough to an Apple Store to go in, they will provide a loner. I am very disappointed in the level of customer service being provided to address this issue. Apple needs to own this problem and make it as easy as possible for customers to get it resolved.

when opening Setting/General/Software updates I received pop up for cellular data update, I updated network it was in regards to my Phone Provider Network plan. Update cellular usage etc.