Visited today without charging.
The charger is in the parking in front of the school. All regular parking spots are indicated "Besucher Schulgasse 5". There's also the trash collect point there. The chargers are probably open to everyone since it's Primeo and there is no special marking apart from the EV signs.
I did not take a picture facing the other way as there were many kids around waiting for the school to resume. I'll try to go back at a time when the school is closed for a general view. There aren't any gate or anything, it was pretty easy to find with just the GPS coordinates.