It is a lock. You open it with a key. Just like a physical lock. And just like a physical lock, there are ways to force it open without the key. And just like a physical lock, forcing it open without a physical key is (usually) illegal.

Yes, but it's a lock where they have to provide the key too, and the only way to prevent you from manually opening the lock is obfuscating this process.

And, like a physical lock, you need to provide the users with the key, so that they can use the product.