code provided for this video - https://youtu.be/XZJ_C3j8_WI. (How to Integrate ChatGPT with Google Sheets Using Custom Functions)

ai-function.gs

function AI(prompt, cellData) {
    // Add a system prompt to ensure output is specific and concise
    var systemPrompt = "You are an AI assistant that provides very specific responses. Your outputs are meant to be placed directly into a spreadsheet cell. If the request is for a number, output just the number with no additional text or explanation. Be as concise as possible.";
    
    // Combine the system prompt with the user prompt and cell data
    var fullPrompt = systemPrompt + "\n\n" + prompt;
    if (cellData !== undefined && cellData !== null && cellData !== "") {
        fullPrompt += ": " + cellData;
    }

    // Set up the request to the OpenAI API
    var response = UrlFetchApp.fetch("https://api.openai.com/v1/completions", {
        method: "post",
        contentType: "application/json",
        headers: {
            "Authorization": "Bearer " + OPENAI_API_KEY
        },
        payload: JSON.stringify({
            model: "gpt-3.5-turbo-instruct", // Updated model
            prompt: fullPrompt,
            max_tokens: 100, // Adjust the number of tokens based on your needs
            temperature: 0.7 // Controls creativity; adjust as needed
        })
    });

    // Parse the API response
    var json = response.getContentText();
    var data = JSON.parse(json);
    var result = data.choices[0].text.trim();

    return result;
}