Visited on Friday without charging.
The chargers are in the P1 parking spot, marked "Besucher". There's a ticket gate, it's the same parking tariffs as the P+R.
On eCarUp this location is listed has having 2 plugs, but there are actually 4 plugs. The chargers and parking spots are identical, but only the left charger has QR codes which match with the 2 plugs listed on eCarUp. No instructions on how to activate the other 2 plugs.