How much is the cost for the unlimited API? Why do i have to KYC to use the api?

I want to use alpaca API live streaming (websocket) data to create an application.

I have gone to sign up but i cannot seem to create an API key? Do i need to KYC and verify first? if so, then why the need to KYC to simply use an API?

Also, i have seen references to the unlimited and free version, but there is no mention of price. What is the cost for the unlimited version API?