You are only buildin up like a gateway. You must have AI itself somewhere. And to get what you are wanting you propably want to host one by yourself. And because demands are really high you will spin up a separate VPS and install that AI there.
So if you have done that then you have to tune up that docker command properly and you are good to go.
But AI is not part of docker or Discourse.
Perhaps you should do what Rober proposed and start with OpenAI. And after that at some point move on.
BTW, those functionalities you are looking for are not that reliable than you may think. And costs at least 60+ USD a month, perhaps 300+ is more close to reality.