This page explains it, basically you don't go to prison itself, but you have certain requirements/conditions (stuff like community work) and if you break the terms you might then get sent to actual prison.
So from my experience of these type of systems (mostly in the context of banking services) they normally want to use your devices camera to take the picture directly, and normally also want a photo of a photographic ID to compare against.
On my Pixel if I plug into a usb data connection it defaults to charge and gives me a notification that lets me switch USB mode. Think this flow has been standard for a while, also seen it on Samsung devices.
Might be there's some other option under developer options.
Is that up to them though? Aren't browsers on iPhones only allowed to be wrappers around the built in safari engine? If that's still true extensions that interact with the web page it's self would probably be pretty limited.
I keep reading that not as the venue doesn't have enough space for everyone, but as the venue has banned certain people. I'm really hoping I'm wrong and it is a space issue.
I think they have stopped doing that on newer models.