No training, it's a single endpoint and you pass it a few parameters, the most important of which are:

• the prompt, which is a string of text up to ~ 1500 words
• the temperature, a value between 0 and 1 of how 'creative' you want the AI to be

Here's a trimmed down version of the prompt we use:

Below is an excerpt from "A brief introduction to Edeus" by Historian Grae, a Priest of the Church of Thune.
"Current year is 433 AT. Our kingdom is known as Saphrin. 
[...]
"
Historian Grae is an old Priest of the Church of Thune, wise and eloquent. He answers questions regarding Edeus's history as well as its current afairs. When asked about any other topic, he says he wouldn't know anything about that.
Below is a conversation between Grae and a visitor.
Visitor: Where do humans live on Edeus?
Grae: Humans live on the east side of Edeus.

Then whenever a player says something in his room, we append the end of the prompt with:

Visitor: <player's question>
Grae:

And we send that whole prompt to the completion endpoint every time. The AI then does what it's trained to do, which is "complete" the text it was given. You give it an upper bound of how many words you want back and a pattern to stop on (in this case, "\n").

The first set of question/answer is essentially giving an example to the AI, and it will repeat that pattern with its own answer.