Car purchased; lowering registered?

Help! I’m absolutely not a car expert, but I’m just getting a little panic. I bought a Seat Leon FR ST 1.8 TSI from a dealer. My father (something more experienced) stood by me while visiting and testing. Now the dealer opposed the “original feathers” when buying it (which he got from the previous quoter). Now I’m not sure if the “lowering springs” are allowed at all (although the dealer let me test driving with [with red] I didn’t notice any other report or a so-called ABE. How do I find out if the built-in springs are allowed at all? (so the car is not extremely deep, but a colleague spoke to me about it and now I honestly said a little panic if I am on the road “illegal” or if the dealer didn’t tell me anything) As a layman, I couldn’t find anything in the vehicle license. Thank you for your help!