Visited on July 5 and did a short charge with AVIA Volt RFID.
The charger is in the parking indicated "Restaurant, Bar, Arzt, Coiffeur, Physio - Surenweidstr. 1". But since it's a Share Birrer location the charging spot must be open to everyone. It doesn't have any signage unique to this situation.
The public green charger has an attached cable and the QR code for 90066. The private purple charger is also visible on AVIA Volt, but that one has no QR and the space is reserved for the car share.
Now the business even have Partino chargers for their own customers, so there's even less risk of finding this one occupied by a customer.