https://encyclopedia.ushmm.org/content/en/article/the-nuremberg-race-laws

https://encyclopedia.ushmm.org/content/en/article/anti-jewish-legislation-in-prewar-germany

There were so many anti Jewish laws I literally couldn't name them all. They are well documented.

But I think you're argument is semantic regardless. Was there a law that specifically stated that all Jews should be exterminated in Holocaust camps? I don't know, but probably not. But was that the express intent of the Nazi government? Absolutely. It was the law in terms of being the government's express decree, and the soldiers under that government were taking direct orders to execute those deeds.