Climate does not cool after service

Hello dear Smart 454 drivers and screwdrivers. I had the climate service done at ATU. You did the sevice, so everything has to be io. But unfortunately the climate doesn’t get cold, the climate switch lights up. Wouldn’t have had to notice this with the climate service if the climate doesn’t cool? How can I check if the climate compressor is running? Have the smart only since 2024 and don’t know me so well from where the compressor sits with the 3 cylinders.