The LLM being used here is ChatGPT 3.5. To experiment with GPT 4.0, you must add this: &theModel=gpt-4&theMaxToken=4095&apiKey=[your got4 apiKey without the "sk-"] at the end of the URL. Be aware, the API key used for these samples is nearing its expiration. However, these examples will continue to operate smoothly if you substitute the current apikey with one of your own.