Got to be lamppost charging, surely? Lights are much lower power than they were, so the wiring would probably support it, or could be adapted reasonably cheaply? The key thing is to do away with any need for apps or cards - just make them dumb plugs, with very little to go wrong. Then control access by parking restrictions as is common in residential roads; you need to pay a flat monthly fee priced in the basis that you are charging most nights, or buy 24 hour displable permits in books of 20 or so. Yes, you’d need to pay for some parking wardens to work at night, but only enough to do occasional spot checks, and they would probably pay for themselves with the fines.