Example, across the whole of my 2.8 million people city, parking is app-to-pay. No meter, no ticket box - just a sign announcing to pay by app and a QR code.
QR code points at a webpage announcing which very limited selection of apps you have for iOS and android and the backup option to ring a number.
Ringing that number means you talk to a person, make an account for only one of the apps over the phone, then use the phone menu system each time you need to park.
If you have a dumb phone(can't scan a QR code) or no phone... you're fucked. No way to pay for parking. Expect your fine and go through the bullshit processes.
The world should NOT think it is great to be so dependant on two US companies, but here we are.