Visited on April 19 and did a short charge with AVIA Volt RFID.
The parking appears to be accessible 24/7. It's free for customers, so presumably same if you come to charge here outside business hours.
The charging spots don't have any signage and are quite close to the entrance, so not sure how available they stay during opening hours.
The QR codes for payment don't work. They link to the short EVSEIDs, but AVIA have not yet renamed the chargers from their default EVSEIDs...
I can confirm CH*AVI*E21290297*1*1 is the leftmost charger, one of the 2 with attached cable, because it's the one I used. Not sure about the matching for the others.