OpenAI API: How do I migrate from text-davinci-003 to gpt-3.5-turbo in NodeJS?

How do I migrate from text-davinci-003 to gpt-3.5-turbo?

What I tried to do is the following:

Changing this...

model: "text-davinci-003"

...to this.

model: "gpt-3.5-turbo"

Also, changing this...

const API_URL = "https://api.openai.com/v1/completions";

...to this.

const API_URL = "https://api.openai.com/v1/chat/completions";

The Problem is that it does not work. The code I will be giving is the unmodified code, so that anyone can help me what to change.

Why I wanted this upgrade?
I was irritated by text-davinci-003's completion. Like sending "Hello" gives me an entire letter not a greeting.

Live Sample (Via Github Pages):
https://thedoggybrad.github.io/chat/chatsystem

Github Repository:
https://github.com/thedoggybrad/chat/tree/main/chatsystem

You're using the gpt-3.5-turbo model.

There are three main differences between the Chat Completions API (i.e., the GPT-3.5 API) and the Completions API (i.e., the GPT-3 API).

1. API endpoint
   • Completions API: https://api.openai.com/v1/completions
   • Chat Completions API: https://api.openai.com/v1/chat/completions
2. The prompt parameter (Completions API) is replaced by the messages parameter (Chat Completions API)
3. Response access
   • Completions API: response.choices[0].text.trim()
   • Chat Completions API: response.choices[0].message.content.trim()

Try this:

const getChatResponse = async (incomingChatDiv) => {
    const API_URL = "https://api.openai.com/v1/chat/completions"; /* Changed */
    const pElement = document.createElement("p");

    // Define the properties and data for the API request
    const requestOptions = {
        method: "POST",
        headers: {
            "Content-Type": "application/json",
            "Authorization": `Bearer ${API_KEY}`
        },
        body: JSON.stringify({
            model: "gpt-3.5-turbo",
            messages: [{role: "user", content: `${userText}`}], /* Changed */
            max_tokens: 2048,
            temperature: 0.2,
            n: 1,
            stop: null
        })
    }

    // Send POST request to API, get response and set the reponse as paragraph element text
    try {
        const response = await (await fetch(API_URL, requestOptions)).json();
        pElement.textContent = response.choices[0].message.content.trim(); /* Changed */
    } catch (error) { // Add error class to the paragraph element and set error text
        pElement.classList.add("error");
        pElement.textContent = "Oops! Something went wrong while retrieving the response. Please try again.";
    }

    // Remove the typing animation, append the paragraph element and save the chats to local storage
    incomingChatDiv.querySelector(".typing-animation").remove();
    incomingChatDiv.querySelector(".chat-details").appendChild(pElement);
    localStorage.setItem("all-chats-thedoggybrad", chatContainer.innerHTML);
    chatContainer.scrollTo(0, chatContainer.scrollHeight);
}