GPT-4 doesn't seem to be set when I'm using the Node.js API

Question

I have set up GPT-4 model for chat completions, and I sent a simple question through the API "what is the model you using for generation text"? and i got the funny ansewer: "I am powered by OpenAI's GPT-3 model for generating text.". but when i asked exact question with gpt-plus in official website i got this ansewer: "I'm based on the GPT-4 architecture, which is a part of OpenAI's Generative Pre-trained Transformer series. GPT-4 is an advanced AI language model designed to understand and generate human-like text based on the input it receives. It's capable of answering questions, providing explanations, generating text in various styles, and even performing specific tasks like translation or code generation, all while aiming to improve upon the capabilities and performance of its predecessors." Does someone have a simple experience?

import {OpenAI} from 'openai';
const response = await openai.chat.completions.create({
    messages: "what is the model you using for generation text",
    model: "gpt-4",
    stream:false,
    temperature:0.2
  })
  console.log(response);

the ansewer was: first Time:

//I am powered by OpenAI's GPT-3 model for generating text.

Second Time:

//As an AI developed by OpenAI, I am based on the GPT-3 model.