Thank you for your question! Yes you will have to use your own API key. But it is 10 times cheaper than the previous Davinci 3 model. 1k tokens cost 0,2 cents. (not even 1 cent!)
Thanks for your response! I am not familiar with unity, but integrating GPT into it seems like a great helpful tool. I actually want to learn unity in the future, so I'll keep this tool in mind! (by the way, the art looks stunning.)