Visited on Tuesday without charging.
The 2 chargers are under the canopy in front of the garage.
There are no specific charging instructions, but there's a QR code above each charger to access the eCarUp ad-hoc payment page.
Only the front charger appears on opendata and the eCarUp app. It shows out of service in the live data, but when you scan the QR code it asks for your credit card just like any working charger.