To use the library, the source code must use import syntax. To do this, in package.json specify "type": "module". The library has one single function "run". Example of use:

import run from "chatgpt3.5";

const getAnswer = async(prompt) => {
    const res = await run({ token: 'token', prompt });
    console.log(res);
};

getAnswer('Hello');

If you need a token you can get it via Network Tab in your Developer Tools on ChatGPT Chat page. But before it you have to send any message to it.