I walked by yesterday. I didn't try to enter the parking, but based on name/address on Swisscharge, it must be the parking under that building, which you enter from the Leutschenbachstrasse.
The sign at the entrance says Mo-Fr 06.00-01.00 Sa-So 08.00-01.00 and has a parking meter sign, but I am not able to confirm if that's still true or has been converted to a ticket machine. The location does not appear in the EasyPark app, so it's at least not integrated with ParkingPay.
I didn't see any other door or staircase around the building. The main foot entrance has a sign "Parkhauseinfahrt Haupteingant geôffnet" followed by the same times as the opening hours on the previous sign. So I guess the foot exit/entrance is through the main hall of the building.
I have not yet found any picture of the chargers inside the parking.