On Chargemap there are pictures from around December 2021 and May 2022 where we see the parking spots are not yet painted. In a picture from around June 2022 the 4 parking spaces are painted green. It's an underground parking lot. The stations are Easee without attached cables.
This must be the parking for customers of https://www.bognengiadina.ch/ but I don't find a single mention of the parking on their website so I don't know if it's also open to non-customers. It's not mentioned on the tariffs page at all either, but I don't think this is enough to confirm whether parking is free.