Visited on October 24 without charging.
The charger is in the outdoor parking to the north of the building, accessed directly from Rorschacherstrasse.
The parking tariffs and ParkingPay number seem to be the same as for the indoor parking. The exterior parking should remain accessible 24/7 for sure, because I didn't see any gate.
I did not find any usage instruction or EVSEID. The only information on the charger are the ecotap plug IDs, which are probably useless unless you happen to call the manufacturer hotline instead of Partino.