iPhone SE 2020 gets hung up in IOS update

Does anyone know how to rectify this? I just bough my son a new iPhone SE 2020 and am trying to set it up as a new phone with a new service provider.

As part of the setup process to transfer everything from his old phone I reach a point where I am forced to update to the latest version of the IOS 13. It's a meager 443 MB of an update.

But...

The phone just gets hung up and refuses to complete the update. I've done this 3 times, starting over and erasing the phone each time, but after waiting 45 minutes this last attempt I give up.

It's connected to a strong wifi network and is already connected to the new wireless carrier.

But the **** thing won't update.

What do you suggest?