Hi guys, I just fine tuned an openai model and I'm at the point now where I need to set the openai api key as the custom llm api key (as it says to do in the vapi docs), however i keep getting the error "Authentication plan must be an object" even though it says OAuth2 Credentials are Optional. I tried adding the key through dashboard and api both with no success. Am I missing something? Are the vapi docs incorrect? How have you guys configured fine tuned openai models without using your own server?