Grab your API key from https://platform.openai.com/account/api-keys , then set it in the extension options (right click extension logo -> manage extensions -> options tab -> copy paste the key in and press submit). After that you can go to any YouTube video with closed captions available and press the extension, which will then send everything to chatGPTs API endpoint and form a reply.
For example, a ten minute video costs around 2200 tokens or 0.0044 dollars, and you get 18 dollars for free since openAI is generous =)
