Visited on May 7 and did a short charge with Lidl app.
The parking is paid (parking meter)! There was a sign I saw too late that was mentioning something about offsetting the parking price. I'd need to go back and take a closer look. I think you might be able to get a "discount" at checkout when providing the parking receipt.
It wasn't super clear where the entrance is. Immediately after the fork from the freeway entrance there's a big Lidl sign with a parking arrow pointing right. But at that point there's no road on the right. Just after the bus stop there's a small bridge forbidden to cars. Only after driving past the entire shop there's an entrance without any Lidl sign. They could have used an arrow going straight then right, ideally with the distance underneath...